are you looking for free assets to learn with or publish with? thats rhetorical btw no answer needed. with free assets and to some extent with paid ones as well you need to pay close attention to the license for them when publishing.
that said theres a ton of places to get assets out there. it really depends on what you want. opengameart.org has pretty much everything with a mix of things. then theres places like itch.io which has some free and paid things. many people sell on gumroad, turbosquid, and sketchfab. theres also many things on the marketplace. sometimes 80.lv posts about givaways. theres also kenny.nl which has some packs that are free if i remember.
of course you could always create your own assets too. you could learn a bit of modeling with blender. or use one of the many voxel based creation methods. or if your really tech savvy you could use photogrammetry to copy things from real life.
theres many many more places out there as well just google a bit and youll find more.