So i made a homebrewed druid subclass (2024 version) and i keep getting the error "Subclass does not have the necessary class features with the correct required levels." 
after some research, i changed the spell list to a level 2 feature and it's letting me share.

my question is, don't the features for all subclasses in the 2024 version start at level 3?

They do, yes. There's a long-standing bug in the D&D Beyond homebrew system where the thing that's checking whether you have subclass features at the right levels is checking both sets of levels instead of just the set for the version you're making the class for. It's definitely not supposed to work that way.

You can get around it by just adding a dummy feature at the other level that doesn't do anything.

This is infuritating. I spent hours trying to get it too work but definitely would not have thought to add a feat to a level before you take the subclass. Goddamn that's stupid. But hey, Circle of Witchcraft now actually published