Is it better to pick specialization in AI/ML for ex Computer vision, NLP etc rather than generalization?

I’m new to the feild of AI/ML and find it hard wich direction to go.

Can the same algorithms used for English speech recognition systems be applied to other languages?

Is data the only thing different here? Meaning if you have written and spoken data of some language, how would you go about implementing the training models etc Any resources?

I installed nodeJs with brew(brew install node@8) but when I run node -v it says command not found(mac).

What are some good technical resources about streaming media(audio) for someone building music streaming web app?

I am not asking about languages, frameworks etc rather encoding and decoding etc.

Are there any resources that teach how to create tools?

Most courses/tutorials/books on programming/cs teach how to use tools rather then create them.