Kaboom.js is very easy to pick up : https://kaboomjs.com/doc/intro
i would strongly recommend taking a good look at an open source game engine like Godot[0] ( which is very forgiving on older hardware[1] ) there are several very good tutorials on youtube[2][3][4] to get you started. If that pick your interest, then Udemy have some more advanced stuff on Godot...
[1] https://www.youtube.com/watch?v=r7xW1tBIwXQ&t=3s
[2] https://www.youtube.com/watch?v=LbORGmdJCfQ
This is the part where I wish there was a 3 month game dev bootcamp. I don’t want it to get a job, I want it because I just wanna make games.
Grab a copy of Unity and take some of Penny DeByl’s courses on Udemy.
r/gamedev
If you're looking for things in the way of tutorials, gamedev.net is generally a fairly good resource and they've also got a lot of articles/posts written on some more in-depth or interesting technical items:
https://gamedev.net/tutorials/
Another great way is just to browse through some open source games and just see how they're written and work. The OS Game Clones website is a good starting point for something in this realm as you can look through clones of games (sometimes even the original source the author has released) you may already be familiar with:
https://osgameclones.com/