Help with coding a game.

Hey everyone, Mapache here.

I need help making a simple endless sidescroller shoot em up. I need it to have pickups that change something from either the scene or the sprites. Is there any reccomendation on what documentation I should read?

Thank you in advance!

(self portrait just to put a picture in here)

https://preview.redd.it/51t3hw6wcwfg1.png?width=300&format=png&auto=webp&s=ed01c437fb0aa19bf8ec345591412fa4039beb5d