Probably a mix of stuff you just like, and stuff that’s level appropriate… As long as you’re open to reading/listening/watching stuff outside your usual interests, you should be able to find level-appropriate material.
When you’re starting out, graded readers are great because they’re designed for learners but they’re not textbooks. Once you’ve finished Genki I you might want to check out the Absolute Beginner Book Club (assumes a mostly N5 grammar level I think). You can still ask questions on completed clubs, and read along with currently active ones!
Nihongo con Teppei (beginner and intermediate) are nice Japanese-only podcasts designed for beginners. He speaks rather slowly, repeats himself quite a lot, and uses a lot of English loanwords to explain things. The beginner podcast is about 4 minutes long, so it’s quite accessible after a bit of grammar and vocab study!
Netflix has Japanese subtitles on most Japanese content available in your country – even if you’re not in Japan! Netfix has quite a lot of anime, which can be fun to watch – it does’t matter if you don’t understand everything, the images will help you follow along a bit, and you’ll hear words you know. The Language Learning with Netflix browser plugin is nice if you want to be able to study sentence by sentence, or look words up while you’re watching.