He went to the first Freddy’s, where he was attacked by the robots, guess kids do resemble their murderous father’s appearance, of which he was able to survive by very obviously staying in the security office, and to make sure he didn’t get rejected for literally having a serial killer as his father, he used fake names, in this occasio, Jeremy Fritz, or something idk. At the end, he burnt down the entire restaurant in hopes that the spirits would be freed. Now I have no clue if these were the ones scrapped in the service room in fnaf 2, but they probably were. Michael then goes to this one, and does something with the robots, but didn’t burn down the pizzeria this time. I’m pretty sure the toy animatronics (the upgraded ogs not including mangle, mangle is theorized to have been possessed by Susie’s dog) weren’t possessed by any dead kiddies, therefore making it unnecessary for him to burn them down, but the restaurant did close down, most likely due to the Og robots.
So later on, some idiot decided that it’d be a neat idea to make a horror attraction based on the missing kiddies and stuff, so he got ,what I think was the original pizzeria, made it creepy, and decided that he needed at least 1 animatronic to actually get customers. Luckily for him, the man himself inside a heavily damaged bunny suit was in the very location, of which afton probably used to his advantage and acted functional. Now of course, nobody knows that the animatronic with the smell of a decaying corpse knew that it had a decaying corpse inside of it, except our good pal Mike, and went to work there, survived his own psychotic father, and burnt the entire place down, thinking he freed the spirits of everyone. Now somehow, Afton survived, and was able to degrade his entire design somehow, and also told Mike before he eventually got spring locked that his sister was still somewhere down in the basement or something.