WOW :vvvv
There is a bug where I get a free chess lesson everyday, even though I'm not premium

Bug?
dude same i can do multiple lessons it says 1 free lesson remaining everytime i click on a lesson

Are you sure you're not doing the New to Chess lessons? Those are unlimited:
https://support.chess.com/article/284-how-do-lessons-work

Do you mean the lessons in the category? For example in Opening Principles the first lesson is Control the Center. Are you saying you can continue in that chain of lessons?
Or that you can open up a completely different one?
Bug?