Do I need to pay rent on a foreclosure house even if I don't have a lease and I plan to move by the 21st and should I get my deposit by and how do I go about it

Unless you live in California, yes legally you are suppose to pay for the rent if you are living in the home. And you are still obligated to give notice, I will assume you gave a full 30 day notice or other if required.

You should get your deposit back if you leave the home in proper condition and also of course gave proper notice.
** sadly if they are losing the home it is likely they don't have the money, did they put the deposit into a separate bank account, many states require that.