Ruby was there when summer died, at the hands of Salem herself, and was given a very small, nearly unnoticeable, Grimm that buried itself right behind her eyes, where the curse of the silver eyes wouldn't affect it, and slowly began to mess with her head and make her a loyal servant of Salem. Ruby took her mother's weapons and left. She learned to use them in secret, using tutorials on the CCT net to watch videos and practiced every move, then learned more by experimenting, writing it down, and practicing until memorized as well. She later convinced Qrow to teach her how to use the scythe, and he realized that she had a perfect recall and was able to learn the forms extremely quickly, and was impressed when she trained them into instinct anyways. He taught her more advanced techniques, which were developed by learning in conjunction with Summer, and is surprised to learn that she learned them the same way he did, by observing hand motions and applying them. He taught her how to shoot a rifle, and a pistol, then sword fighting as well, all of which she picked up well. She didn't train it all into instinct, just the scythe and rifle, then did her own research into fighting with pole arms and warscythes/pole axes, and developed her own style, soon afterwards unlocking her semblance of speed, which had a side effect of releasing rose petals from her clothes. Soon after her semblance unlocked, she took a day everyone was gone and ran back to where summer died in the snow, and hunted down the cloak, which, while white, had become so soaked and imbued with blood that she had to dye the thing red to hide them, and she began wearing it religiously afterwards. She eventually made it to beacon, after stopping a robbery by Torchwick and impressing the headmaster.
After initiation and all that jazz, in the second semester, Ruby starts to have headaches and blackouts, in which her friends and sister tell her that her eyes turn red and the whites turn black, and she's horrified, does research into possession type Grimm, asks the headmaster about it, confronts him about how old he is, and learns about who Salem is, then logics out her silver eye superpower, and begins trying to get the Grimm out, fails, and becomes completely possessed, and her unique silver eyed power is the ability to pass her silver eyed powers to her most treasured person(Qrow), who becomes worried and comes back early because he has silver eyes all of a sudden. Ruby runs from the school, with black eyes when they aren't possessed, leaving behind all her weapons, and starts living in the forever fall forest, where Qrow and rwby and jnpr hunt her down. She admits to all the Salem stuff, learning about her mother's weapons, which rwby found after she left, the Grimm she knows is possessing her, and the fact that she thinks she'd have to die to keep it from killing her friends. Then she gets possessed again, and they have to fight super powered but unarmed ruby rose, and are losing handily until Qrow figures out how to activate the silver eyes, and kills the Grimm in her head, after which she goes into a coma, and has some character development courtesy of the brother of light before she wakes up with the intention of making Ozpin realize that Salem is pivotal in keeping people United, and that the gods had no intention of interfering in the world any longer, despite what they said about the relics, and he could gather them and defeat Salem if he wanted, but he would need to become the big bad guy if he wanted to keep the world United. The gods have left and aren't coming back.