I need to know my rights as a tentant renting a room in a house that is going to foreclose in the state of California.

You may pay rent and live there till it is foreclosed. The new owner will have to give you notice after the sale to evict you.

You can not stay without paying rent.

If the owner is moving out you will need to make arrangements to pay or have utilities put in your name

You will have 90 days after the foreclosure is finalized to move. A foreclosure can be stopped right up to the moment of the auction so until then you have to continue to pay rent. Depending on whether you have a lease or not, you may be able to terminate the tenancy and move sooner.