I have still yet to learn how to make an actual repertoire
Find an opening (or two, three MAX) to play as white. Then find one for black against e4, d4, c4, etc. Once that's done record lines and what you want to play. Also maybe throw in a setup-based opening like the KID to play when you have no idea what you're facing (aka a weird gambit-type opening). Then just practice and elaborate on it more. Choose openings you'll probably use for the rest of your life. Magnus did!
Thanks for the advice. I usually play Italian game, London system, and King's gambit for white (yes, I play e4 alot out of habit) and French defense, Caro-kann defense, and KID for black. What I think my main struggle is after the first 3 or 4 moves of an opening, I just go autopilot (meaning I don't know what I'm supposed to do next so I just push and develop randomly) and I'm not used to responding to counterplay from my opponent (for example I play the KID and end up letting my opponent have 2 pawns without trying to stop it).
I have still yet to learn how to make an actual repertoire
Find an opening (or two, three MAX) to play as white. Then find one for black against e4, d4, c4, etc. Once that's done record lines and what you want to play. Also maybe throw in a setup-based opening like the KID to play when you have no idea what you're facing (aka a weird gambit-type opening). Then just practice and elaborate on it more. Choose openings you'll probably use for the rest of your life. Magnus did!