Hi all, I'm new to all of this and not even sure if this is the place I need to be

I recently had a book that I'd written converted to epub so that I could put it on Lulu and sell online however it hasn't turned out how I imagined.
Before I reformat and try again I wondered if people could give some advice?
- do links work in epub? Mine don't seem to at the moment
- Should I just put everything into the same font and font size?
- Is there anyway to keep certain aspects together? For example if I have a quote I would like it all to show on the same page and not be split up?
As you can probably tell I'm not that literate with all of this however I love learning this stuff and I'm eager to get things looking good so I can get my book out there.
Thanks so much if you have made it this far in reading my essay!