Big commercial books stores like Barnes and Noble are garbage, they're expensive and much of the time don't even have that great of a collection. Now with independent books stores we have to make the distinction between used books stores and not. While new, independent books stores are better than big chain bookstores, it's not by much. Now a good used books store is great because usually they have a wide selction of quality books for cheap prices. Also, libraries sometimes have a little bookstore where you can get books for usually only a few dollars, which makes it worth checking out. If you want to buy used books online, amazon, ebay, and biblio are all good choices - I especially like biblio.
The two best sites for getting books digitally are libgen and b-ok. You can find almost anything between these two sites.
I really encourage anybody to dismiss everything they've ever heard from reddit, english teachers/professors, and the booktuber crowd - generally terrible influences. In reality it isn't hard to read a novel, it just requires time and a little bit of effort on your part. It is not just an activity for nerds. Don't be a brainlet. You might have heard online somewhere to start with the greeks, generally I think it's good advice.
For Japanese literature I'm no expert but this is a nice chart.