You could try these game engines to mess around. They require very little knowledge of programming. Both have resources to get you started.
https://ctjs.rocks/ (free)
https://www.yoyogames.com/get (paid)
Other than that, you should check out resources listed in r/programming and similar subs.
Apples and oranges.
Yes, there are a lot of Javascript based game engines. Phaser is a very popular one. Ct.js is a game engine with an IDE, very very accessible.
You'll be hard-pressed to find React based game engines. Boardgame.io is a turn-based game engine with built-in React bindings.
We should start a game engine subreddit. Its annoying that people get so mad when you want to discuss game engines.
With such an under powered PC its hard to say. There are web based 2D engines that run on anything such as https://ctjs.rocks/
Godot is pretty small too, if you switched to Linux I bet it would run great. Windows 7 I am not so sure.