If you learn here or there will benefit you (depends on what your project is), I would say if you want to go ahead learn both no harm
I learnt here and elsewhere, there's a lot to learn(advanced and in depth) I'm still studying theresthere's no end and the field is huge. Urm Google search or YouTube tutorials if you looking for something. MDN is a great website.
list of courses & resources
If you are looking for something in specific let me know and I can point it out