Some more things:
CODE:
In the words of Mystake, "ENDURE!"
...or ask for help via the proper forums/reddit if something happens like you have an emotional breakdown while trying to add a walljump for 2 hours that'll push you away from the wall as a beginner that wont give you infinite wall jumps but everything is breaki-
GAME PAGE:
Refer to other pages to help create your own game page, see the patterns of the popular ones to see why they are capable of hooking players, and use the new knowledge to create your own. do not use AI dialogue.
MUSIC COMPOSITION:
OP touched on this a bit, but if you wanna expand past using YouTube to find royalty free music, there are sites like Artlist that have an entire database of royalty free music.
Some of these sites are free, some are subscription-based, but these sites do exist.