I want to know how to change the colour of the hair and stuff because I don't know how to do all that stuff.

First go to https://jpegsarebad.github.io/celeste-editor/, that edits the map. Then you save as a .p8 file, and go to https://www.pico-8-edu.com/, which you drag your .p8 file into after pressing play, then you can play the game. Press escape to see the code, edit it, and if you press the sprite button on the top right, you can change the color of the hair, but if you want to change what color it changes to, you have to edit the code directly.

I thought i could put stuff in the editor in pico 8 education edtion cuz its a very lazy mod

The code is pretty readable for hair color, and sprite swaps are pretty basic

ok

Just make sure not to overwrite any of the glitchy looking sprites because that's where a good chunk of game data is hidden, if you want to mess with things and see it work without using anything but Pico 8 itself look into the built in demos, specifically jelpi