In this timeline, Steve has told Tony about the death of his Parents by his best friend Bucky Barnes, he did this while Tony was surrounded by everyone that cares about him, he is angry at first but calms down after Steve has explained what happened, the HYDRA brainwashing, that he wasn't responsible for his actions, Tony eventually calms down, he agrees to help Steve look for him but cannot do so, the events of Age of Ultron still take place, Thor returns to inform the Avengers of what has happened in his quest for the infinity stones, The events of the Civil War still happen but Thor is present, Ross tries to convince the Avengers that they are dangerous, Thor does not take this lightly, he defends the Avengers, Tony fully trusting Steve despite his guilt, Steve explains that the actions of the Avengers saved more lives than it took, Tony, argues that the World Security Council fired a nuke at civilians in New York, Natasha and Sam adds to this by saying S.H.E.I.L.D was infiltrated by HYDRA, and if Steve hadn't brought down the Helicarriers that many people would have died, Thor goes further to say that the Avengers will not be controlled by this tiny human govenment, Ross insists that the Avengers sign the Accords or face imprisonment, Thor fires back, when Earth is in ruins and civillans dead, then the accords will be reconsdiered, Ross looks stunned, Vision adds in saying that the disadvantages of applying the accords to the Avengers would far outweigh the benifits, there may be conflict but it is handled with minimal loss, Ross tries one last time by threatning the Avengers with imprisonment, Thor replies that he will take the Avengers to Asgard, where they will be safe, Ross is now out of options, either have the Avengers imprisoned so the world will never be safe or have the Avengers never be on Earth, he relectuntly gives up and immunises the Avengers from the accords, Thor then leaves for his journey for the infinty stones, the bombing in Vienna still happens, Bucky is framed, thsi causes the Avengers tp be split, one side supports Steve whilst one side supports Tony, T'Challa wants revenge, Bucky gets captured, Zemo activates the Winter Soilder, Cap stops a chopper, but now the conflict is different, Tony wants Bucky to pay for his crimes, Steve wants him rehabiliatd, he finds out who really bombed Vienna The Airport fight scene still takes place as Ross orders Tony to bring in Sergent Barnes and anyone who asscoiated with him, Tony recruits Spider-Man, Steve recruits Ant-Man, the sides stay the same, the airport fight scene still takes place, this time no one gets arrested due to Tony's side saying only Bucky was there,everyone else is allowed back or allowed to go back to their normal lives, Rhodes isn't injured due to a parachute Tony put in the suit, Black Panther still gets electrocuted and tells Everet Ross her involment forcing her to go on the run, Tony with Bucky and Steve go to Siberia, T'Challa follows close by, the siberia scene takes place, Zemo kills all the Winter Soilders and shows Tony the footage, Tony looks on with tears but he doesn't attack Bucky, knowing that it's not his fault, he thanks Steve for telling him, Zemo looks in shock as his plan to tear the Avengers apart has failed, T'Challa overhears Zemo admitting his involment and arrests him too seeing what Tony did despite his anger, he encounters Steve, Bucky and Tony and offers to help Bucky clear his HYDRA brainwashing, The Avengers except Natasha are still together, Tony still reads Peter's messages every once in a while, this is where the story begins, a story where the Avengers were never split up, a timeline where the events of infinty war will never take place due to this version of Thanos and his forces dying in 2023, the Guardians still form as Ronan followed the last order of Thanos and then decideds to destroy Xandar, the timeline then follows MCU cannon, the story takes place just after the events of Civil War*
The story starts by showing the new Avengers Facility, it shows Tony working on a desk with his Friday A.I system, he is working on a brand new armor with a silver/chrome coloring below the chest, he asks F.R.I.D.A.Y to build it before sitting down and overlooks a clear sunny day over the lake, he begins to relax, before he is interrupted by a ringing on his wrist, he looks down to his wrist to see his watch blinking, he reluctantly passes his hand over the screen and it displays a hologram of Steve, "Tony, if you aren't busy we need you in the briefing room" asks Steve, "Of all the times you need to talk to me, you choose the exact time I took a break" replies Tony, a little cross about his break being interrupted, "It's important" Steve highlights his point. "Fine, I'll be there, this better not be Ross again, where's Thor when we need him," Tony says nonchalantly. "It's Fury, something about an emergency" Steve reassures him
Scene changes to all the Avengers in a meeting room, Sam, Rhodes who can move normally, Steve, Tony, Wanda, Vision, are all seated around a table, they are facing Fury, he has a hat and is carrying something in his hands, "The Avengers were created to protect the world, you stopped Loki's invasion, you stopped Ultron from committing a planet-wide genocide and you managed to not tear yourself apart when the accords threatened to limit your freedom" states Fury. "If we didn't have Thor's help, we may have done so" replies Steve "And I'm glad, if the Avengers were split, I would have had to call Carol," Fury says, "Who's Carol?" asks Tony. Fury turns around to see all the Avengers looking at him "Carol is the reason the Avengers exist, I met her 19 years ago, she tore an armada of alien ships in half by flying through it" Fury casually replies "So if you had someone like that why did you form this team?" asks Sam "Because the universe is a big place, she can't be everywhere at once" Fury fires back "So are we going to meet this Carol then?" asks Rhodey "In time, if you all fail to protect the world then she may just turn up at the doorstep, or if I'm just bored" Fury states "So why call this meeting then?" asks Wanda, "The world is far from normal, part of Congress still wants you to sign the accords and the world knows that that the Avengers was nearly toast, keep your head down for a year or two and act in small teams, the world needs you and keep protecting the world" Fury says, gravitating everyone to his speech, "So you just came down to give us a pep talk?" Tony asks questionably "Yes, and if you don't mind, I'm going to tend to my garden, the daffodils aren't going to grow out themselves!" replies Fury he then walks out
The Avengers then sitting on bean bags begin to talk, "So what do we do now?" asks Tony, "What Fury said, if there's any trouble in the world we act, we keep destruction to a minimum and keep saving the world" replies Steve "So what are we some heroes for hire then?" Sam asks "At least you won't worry about me blowing up a building" replies Wanda, Vision then looks at her "What you did, we know that you did not meant do, it's in the past, mistakes are what we learn from, Captian Rogers was not the super soldier on his first day, Mr. Stark couldn't even fly properly at the start, Wanda does not blame yourself, what matters now is you practice and learn" Vision says calmly, Wanda looks back with some tears, "Thank you" she replies "It's not the same without Nat" replies Steve. "Where is she?" asks Tony, "I have no idea, she could be anywhere in the world" replies Steve. "Wherever she is, she would be protecting people," says Sam "We have to get her back" Wanda states "We will Wanda, just not right now" Steve states "How are we going to find her?" asks Rhodes "We need someone who knows her incredibly well" says Tony "We can't ask Barton to come back, he retired permanently" says Tony "It's that or have one our friends, one of the team still out there in the world" replies Sam "We'll start on it tomorrow, everyone get some rest, the world may need us in any given moment" Steve commands "If we not on the same page of the accords you wouldn't be doing this you know" Tony states with a smirk on his face, Steve turns to him "Go and see Pepper Tony" he replies, "What are you, my calendar?" He heads off to see his girlfriend
Tl;DR: Civil War happens differently, Avengers never break up, Natasha is still on the run, Fury says Carol's the reason the Avengers were formed
As for timeline, Thanos if this timeline goes to 2023 dies, Endgame and Infinity War never happen in this reality, assume the Gamora of 2014 and Nebula of 2014 goes back to their appropriate points in time due to Tony using the gauntlet to restore the timeline in my story, Gamora and Nebula know what happened to Thanos