I want to know how to code a wall jump into my game

i’m working on a game by the name of project hoplings, a platformer with enemies, collectibles, and even secrets. i’m going to add movement tech to the game, like wall jumping, diving (B button), crouching and more, but i don’t know how, exactly. i’m going to need help coding these into my game, starting with the wall jump. thank you.

Pretty sure this has been done before. In an Arcade tutorial on their YouTube channel, there was a 3-part series on platformers. The 3rd episode has wall-jumping: