Publishers: You can use publisher websites to look for similar books based on one you've already found. All of the "big 5" publishers have imprints that are under them, so you can search for those, too. (ex. Little, Brown and Company is an imprint of Hachette Book Group).
Hachette Book Group -link is to sf/f page - search by Genres tab for others
Orbit - s/f imprint
Macmillan -link filtered to Fantasy, Horror, Thriller, Mystery, Romance, Science Fiction
Tor Publishing Group imprints -sf/f, horror, romance imprints
Online magazines, review sites, etc. - there are lots more than these. These are just a couple examples.
Tor.com - sf/f publishing imprint and review magazine, with original short fiction.
Levar Burton Reads - audio recordings of short fiction. Often genre fiction.
Fairy Tale Review - "Fairy Tale Review is an annual literary journal dedicated to publishing new fairy-tale fiction, nonfiction, and poetry."
Libby app - public library ebook/audiobook platform, available with your IndyPL card.
Hoopla - another public library ebook/audiobook platform available with your IndyPL card, with a robust graphic novel/comic collection. Create a free account with your email and library card number.
Don't forget your hometown library! Check what books might be available through your public library's apps/services.