Mkay so I have a few examples
Generally the side of the head shouldn’t be completely round (unless that’s your style or it’s chica lol)
The foxys have triangular ones usually
Although Funtime foxy has a more rounded look.
But don’t be too concerned about some smaller details, you have an artstyle so you should follow that as well. It’s good to have references for whoever you’re drawing, and you can just save the image of the character you need from their page on the wiki