FNAF 2 is a prequel

Notes:

The games are going backwards in time.

Prepare for a mind screw… and possibly major spoilers.

FNAF 3 would be, again, before the first two. It's where everything started using the 4 animatronics from the first game. For unknown reasons at this time, that restaurant shut down. Unless I missed something, it could even be in the same building as this game. The Atari style mini games in FNAF 2 are possibly explaining what happens in the story of this era and hint at what happened.

FNAF 2 as we see is really pushing the grand reopening. The new and polished bots are used as well as the originals for parts. As the story of the game progresses, you see that everything is failing on top of hearing the stories from phone guy. It's safe to assume that everything going wrong is what's described in the newspaper clippings from the first game, FNAF 1. The bite of 87 takes place during this game.

This brings us to FNAF 1. The most current dated game. Freddy Fazbear's Pizza has managed to reopen at a new location, though now downsized due to budget cuts. The building is smaller and power at night is now run by a generator. They've cut out the flashy newer polished bots and are reusing the first 4 we were introduced to. This also explains why phone guy is in FNAF 2 and his final call in FNAF 1 is him losing to the bots.

There you have it. Hope this explains things.