[fundamental]

If you have decided to stay in javascript then I wouldn't be of much help. Most of my focus is on hard-realtime audio generation and processing and languages like javascript are unsuitable for that task. C/C++ introduce a variety of new concepts which may lead to a steep learning curve, but the same can be said about learning many other languages for the first time. Additionally I would like to say that audio programming and music theory are very separate areas when it comes to learning each topic.