Before we talk about my first year, I want to explain how the cover up of the wizarding world worked, as i'm sure you all have many questions regarding this.
It took a lot of resources and planning, but we were ultimately successful. As i've already said, Joanne had us send copies of the first book back one year using a time turner. We did this by temporarily occupying a Scholastic Warehouse, who were the Muggle publishers of the Harry Potter series. We modified the memories of all the people who worked there, so that they would forget that they did so and stay away. We also placed Muggle repelling and Unplottable Charms on the building. We took several large crates filled with thousands of copies of the book, and sent them back in time one year. Following our confirmation that the book had been published in 1997, we reversed the spells on the workers, left the warehouse and the rest of the series was released in Joanne's chosen time frame.
The person we sent with the books was a convicted criminal who chose a sentence of remaining in the past as an alternative punishment to life in Azkaban. He had a tag put on him with a Permanent Sticking Charm, which would activate if he tried to alter the past in any way other than the way he was instructed to. He was simply to modify all the memories of the Muggles who saw himself and the crates arrive, so that they would think they had been expecting it, and distribute the copies out to the Muggle World. Joanne at that time already knew she would be writing the story and that she'd suggest a cover up like this, as she was confident our side would win the war, so she would remain in the Wizarding World until the war was over to avoid accidentally seeing her own book before she wrote it. If the criminal messed with anything else in the timeline, the tag would send him to a special maximum security cell in the middle of the Pacific Ocean, with no chance of escape.
Now, obviously, the Muggles in places such as Little Whinging, Great and Little Hangleton, Bubbleigh Baddington and several others were more of a difficult challenge. With the exception of the Dursleys, Horace Slughorn and Arabella Figg, every resident of those places had their memories modified so that they would forget ever having lived there, and each of the places were rendered permanently unplottable. The Muggles were transferred to live in the nearest city to each of those places and false memories were placed in them of them having always lived there, as were in their neighbours. The Dursleys and Arabella Figg moved to Guildford after returning from hiding following the Battle of Hogwarts. Horace Slughorn now lives in Glasgow. Ottery St Catchpole became the second place in the UK after Hogsmeade to be entirely magically populated, apart from Demelza's mother, who is a muggle. That house was converted into a wizarding one.
All of this was done in co operation with the Muggle UK Government, with Minister Shacklebolt and the Muggle Worthy Excuse Commitee consulting directly with Prime Minister Tony Blair on how to cover up the erasure of several towns from existence. The first chapter of the 6th book was partially made up by Joanne, specifically the parts where incidents such as the Brockdale Bridge, the double murders, and the West Country disaster were discussed. None of those events actually happened. They were made up by Joanne as part of this cover up, to make the story fit less well with the real life timeline. Death Eater attacks did happen, but the real ones were instead covered up in reality as other notable Muggle disasters from that year, such as the IRA Manchester Bombing, which was really a massive blasting hex set off by Bellatrix Lestrange, Antonin Dolohov and Augustus Rookwood at the same time, 3 days before they partook in the Battle of the Department of Mysteries. There were also a number of other smaller murders and incidents that took place that summer, caused by Death Eaters, that were passed off as Muggle caused incidents.
The rest of the conversations mentioned in that chapter were real and were obtained via the tape recorders placed in the Prime Minister's office. Joanne deliberately didn't mention Margret Thatcher by name as having been the person who tried to throw Fudge out of the window. As funny as that would have been for you muggles, it helped to fit the story less well with reality by calling the previous Prime Minister a man instead. Fudge really was sacked and replaced by Scrimgeour, and he really did introduce him to Tony Blair, but alongside John Major, as he had been more familiar with Fudge and Blair had only just been elected a couple months previously, and after extreme public pressure following Voldemort's appearance at the Ministry, after he had spent all year denying his return, and there wasn't anything else that led to it. Joanne made it seem like only one Muggle met Scrimgeour, again as part of her way of splitting this aspect away from reality.
It was a long and arduous process, but it was effective, as until now, you had no knowledge of those places ever actually existing, did you?