I just 100%ed the game and there any complete sources on how todo it so I felt like writing this, sorry for any spelling errors I'm tired asf.
To complete Night 1 you just listen for Bonnie's or sometimes Chica's footsteps/click lights (for the no headphone people) then close that door. Foxie can attack on Night 1 but she can only attack at 4-5am and if you use cams, not at all.
Night 2 is where Foxy is really In play attacking at 1 am if you don't look at cams. The best technique used to deal with Foxie is to spam cams on and off cams. the longer the cams are ON the longer you can delay Foxy from progressing in stages. If Foxy has left booty-Cove you go on Cam 2A to speed it up witch isn't good for power but makes the nights easier to deal with. You DON'T need to on booty-Cove cam. bonny and Chica will actually come at your door consistently. But as long as you check for Bonnie and Chica as stated it will be EZ .
Night 3 is a decently harder as Freddy becomes active. use the same strat form Night 2 with a few changes. The way to deal with Freddy is to be on the cams, you DON'T need to follow Freddy. first is set a 15-18 seconds timer (idk remember the exact numbers) as soon as the night starts and when it ends you should try to stay on the cams a little longer to delay Freddy. As Freddy will run a timer and when its up it will check if your on cams and it not she'll laugh and move. She will start on Cam 1A --> 7 --> 1B --> 5 --> 3 --> 6 (sometimes back up to 3). She can only kill you on cam 6. The way to stop here is the either close the door or look at Cam 6 frequently.
Night 4 is where I've seen people get stuck. Night 4 is tricky but if you use the given strat you'll be okay. one thing to keep in mine is if you want to check on Foxy but Freddy is already in Cam 6 just close the right door (best when Chica is there) and look at Booty-Cove then switch back to 6 and open the door. the later that stages Foxy is in the more frequently you got yo check Foxy.
Night 5 is very hard. You need to be spam flipping the cams non-stop and because your doing that you will need to check the door lights as it's very easy to miss the footsteps in this night. one thing I like todo that you feel out for yourself is when I hear footsteps and close the door with either Bonny/Chica I quickly check the other door to make sure that the other one didn't come at the exact same. Beating this night will unlock the 2nd sex scene for the main 4 animatronics.
Night 6 is where you got to put all of this together and also need good RNG (luck) as if Foxy runs 3 times that very unlucky.
Night 7 (4/20 and other) 4/20 is stupid hard. You'll need to get good at the stuff I have mentioned and get good RNG. Night 7 Codes Fr/B/C/Fo 1/9/8/7 this will unlock a new call where you will learn the Code 6/9/6/9 this code will give you a way to get Golden Freddy sex scene other then by chance and will increase completion % . If you complete the 1/9/8/7 Night it will also add increase completion %
Some Other stuff, if you click on the breasts of Freddy on the poster in your office too much Golden Freddy will crash your game. if you click on the light blue donut in your office a sex scene will start. I also heard of a easter egg puppet sex scene, But I can't confirm it if any one fines it pls tell me.