I highly recommend Feasting’s Ministrife pixelings (https://feastings-old.tumblr.com/tagged/pixelings) and Cairovercoat’s background tiles (https://cairovercoat.tumblr.com/post/49741463009/you-can-browse-through-all-of-them-online) as decorative details!

I definitely agree with Neocities being a good option, know I know Nekoweb exists too. I personally have a predominantly Homestuck fansite and an exclusively auspisticism themed site both on Neocities. I pay money to host multiple sites on the same account.

I highly recommend learning some Javascript after getting HTML and CSS down, as that expands what you can do a lot.