Book reccomendations! Help me get back into reading by suggesting some books :)

Hey!! I want to get into a really good franchise again, its been too long. Growing up, I was definitely one of those LOTR/Harry Potter/Percy Jackson type of people. Nowadays, I really like murder mysteries (although they are usually stand alone books, not series), thriller, suspense, science, fiction, really anything.

I have a special interest in anything Earth-related (I love environmental science) although I haven't found a book that revolves around that (since most are scientific journals lol). That's super niche. but if you have any reccs, lmk!!

Overall (even if it's not envio-science), do any of you have a good franchise that makes you want to keep reading and has really well-made characters? Thanks! Sorry it's sort of vague, it's been so long!!

(also, preferably a series that can be found online! i live in a place right now where it's hard to find books in english)