Online, non copyrighted novels for B2 english level

Hello everyone. This is my first post. I think so! I am from Greece and I am an english student. I'm looking for some english ebooks (novels, fictions etc) to download legally from the internet. My english level according to Common European Framework of Reference for Languages (CEFR) is between A2 to B2 or perhaps between B1 to C1. So, is there something for my needs?
Thanks in advance.
I forgot to mention that I've already searched this amazing and so helpful forum. I found some suggestions in some post, but it's not clear to me if all these are free or you have to pay, and the knowledge level as well that they are related to.