what can i do with just a little knowledge with c# or javascript

The question is too vague to answer.

Programming is not trivial, game development is not easy, so with "just a little knowledge" you'll end up doing "just little things". Also, "just a little" could mean anything, what do you know? What have you done already? Maybe you only know the syntax of the basic loops, or maybe you've made some generic excercises, or maybe you've done a basic calculator... You should be more specific.

Also, you need to learn programming concepts too (paradigms, patterns, and A LOT more), not only languages. Languages are just tools, ideally you can do the same thing using any language with more or less work.

Maybe you can learn to use Unity (it supports C# or JavaScript) and you'll have a lot of stuff already solved, but even then you need to learn more than the basic.