The Roblox-API allows you to do e.g. spawn a explosion in a one-liner: Instance.new("Explosion",game.Workspace) It allows you to do almost anything a game would need (GUI, networking, physics, databases, you name it), with a very straight-forward API. Checkout https://developer.roblox.com/en-us/api-reference , they also have AWESOME tutorials which also explain some mathematics https://developer.roblox.com/en-us/articles/CFrame-Math-Oper... Roblox made learning these various disciplines straight-forward and easy, I still benefit from it today!
Though it also taught me some ... less favorable habits, as they are more common place. Think of: Continuously calling wait() until something loaded, Excessive use of globals, overuse of strings, coding single god-functions that do everything (with a frick ton of redundancy). Remember who the demographic of Roblox is: kids and early teens. The people who create the scripts for it are also fairly young, think teens to young adults. So bad practices are more common here, especially in some YouTube-videos (seriously, some are terrible learning-resources).
If your kid is curious, give Roblox a try :D