Project Selling Failed!

I wanted to sell my recent side project https://www.onlibrary.site/ , on which I feel very proud.
Till today, 46 users have signed up on onlibrary and 72 have been downloaded. Its user base is increasing gradually. But I don't know how I can scale it, how I can get copyrights for the books, and then change it for commercial benefits.

And yes, I also need money for my studies and for other side projects.

If you have interest in it -
https://tinyacquisitions.com/tinyproject/onlibrary-short-for-onlinelibrary