how can I store on the esim

I was able to transfer a lot from my android phone by using AirDroid but I can't do anything with it because my icould is full.

I want to store on the esim. How can I do that? How can I find out how much space I have on my esim?

I transferred from an android to an iphone and I need to transfer my music but I can't because I don't have an app for it. Is there a free app for music?