Given that OP is familiar with C in past, familiarity with types might make the learning curve a bit smaller. I think I’d echo the rec that starting with plain JS is ok, but one need not wait until a sense that one has “mastered” JS before moving onto incrementally adopting TS, especially since the type signatures on VSCode APIs use many advanced features like generics. Typing a functioning JS library is a good way to learn, later on going through collections like https://github.com/type-challenges/type-challenges can help if you need to lookup recipes for specific concepts