https://standardebooks.org/ebooks

This website creates free ebooks from books in the public domain. You can download as many as you want.

You can sort by genre, length or popularity. Download a few options starting with the shorter reads so you can get a feel of what you like reading.

Since they are free, you don't need to feel bad about DNF(did not finish) and moving on to find something you enjoy more.

Good luck!