Since it’s lots of IT guys here, so there is a question -
Does anyone know how to build a (raft) music streaming app?
What is your background?
What are your skills in CS?
Anyway here’s a course for c++ https://www.edx.org/course/introduction-to-c-0
And I believe there was a free course on the Udemy for that.
If you want someone to create the app for you, here’s a place to start with https://vironit.com/how-to-create-a-music-streaming-app-like-spotify/.