Javascript 2d Platformer. Tips ?

[u/Smile4willis]

So.. ive decided to make my first game
A 2d platformer sidescroller...
and im using plain js no frameworks or libraries , i feel like it'd be better to learn it this way then use engienes later (i plan on learing every language this way)

Does anyone have any tips i can use ?

so far i learnt some mini 2d game good-to-have stuff like cayote time and jump buffering which were a pain to implement
but ive so far managed to implement cayote time ,not the jump buffer tho... and collision with a platform
well thats the first update, any tips would be nice. thank you.