Tip: If you give a Muncher tile custom graphics, it will still act like a coin when a silver P-switch is active, whether it looks like a coin or not. So make sure to use ExAnimation if there's a silver P-switch in the area.
This are VL-Tones Docs to SM64 Hacking. It conists any of the general basics to start with it. From Level Scripts to Geo Layout of Mario and Peach. If you're new to SM64 Hacking, this is the first thing you should read.