I've found a really good book series that's kinda introductory to sci-fi is the Waking Gods series by Sylvain Neuvel. Genuinely a really awesome series and after finishing the first one I even dropped an email to the author since I was reading it during a really stressful time and it gave me some escapism. I got a really lovely email back. If you like sci-fi, I'd definetley recommend it, they're just complicated enough to be really interesting