First of all, congrats on downloading these books and wanting to read them.

I can't read much anymore because of an eye problem, but I used to read a lot, mostly "classics", and majored in English, and these are my tips for it:

If you're reading one of these books and feel discouraged 50 pages in, skip to another book. Forcing yourself to read a book that you're not enjoying will set your progress back. You can go back to the book later.

If you feel the same thing with the next book, take a break and read something that you can breeze through and know that you'll enjoy (e.g. Vonnegut or Stephen King) so that you don't get burnt out, but are still in the habit of reading.

Maybe save Ulysses for later. It's really hard, even for the people who are best at reading it. Like, everyone who has read it knows that Pete Buttigeig has not understood it at all and is just posing, even though he built his brand around being the Ulysses guy. It's also full of references to other "classics" that will just be dead spots in the book to you if you don't know them. If you want to read it now, though, because I know it's tempting, read A Portrait of the Artist as a Young Man, Hamlet , and The Odyssey (or at least a spark notes of it) first. Lots of Ulysses is about Hamlet. Ulysses' structure, characters, references, etc. come from The Odyssey, so you'll be missing out on a lot of jokes if you don't know it well enough. I can see The Odyssey being really boring if you're not specifically into that stuff yet (you will be eventually if you aren't yet) but I read the spark notes as a kid and they were as fun as anything. Ulysses is a sequel to A Portrait of the Artist as a Young Man, and reading A Portrait of the Artist as a Young Man will teach you how to read Ulysses, since it uses a lot of the same literary techniques in a way that's a lot easier to understand. It's a book about a boy growing up and being cringe and thinking that he's better than everyone around him. A good example of the cringe is when the main character is late for school or something, and his dad calls him a bitch. The main character is like "Heh. Wrong. A bitch is a female dog." This main character ends up being one of the 2 main characters in Ulysses, and the cringe continues.

The Odyssey, Hamlet, and A Portrait of the Artist as a Young Man are all "classics" themselves, and they're all public domain.

Something that took me a long time to figure out is that no author is perfect at everything, and that you should mostly judge books on what they're good at. If you read a book, and it's the saddest thing you've ever read, it should get huge points for that even if everything else about it is bad. If you read something where every metaphor blows your mind but the plot is boring, it still gets huge points for the metaphors. Eventually, you'll see the best of everything, just not all in one book. Every "classic" has something amazing in it, but can also have a lot of garbage. You have to be like a gold prospector looking for the gold in every book, and not dumping out a pan with big pieces of gold just because there's a lot of dirt in there too.

I don't really want to recommend anything, because a book can be good or bad depending on when you read it, but Moby-Dick is the GOAT, as other people here are saying. It's on the same level as Ulysses, but doesn't have a bunch of references to other books that you need to read first. You do probably need to have read a bunch of other "classics" first just to understand how to get the most out of Moby-Dick when you're reading it, but there aren't as many references to specific books. If you grew up Christian or know a bit about the Bible just from hearing about it, there's nothing specific that you have to read before Moby-Dick. You'll be ready to read Moby-Dick before you'll be ready to read Ulysses, and Moby-Dick is THE BEST.