A. Attend the auction and see who the winning bidder is.
B. Check the property records to see who gets the deed. or
C. Wait for the new landlord to contact you.
They will have a right to evict once they purchase, and if you can't come to terms they're either going to pursue an eviction or perhaps pay you "key money" to move out.
You can always check the docket for the foreclosure case and contact the attorney for the lending/foreclosng party. It is quite unusal that they have filed a foreclosure case and did not serve you. However, check with Clerk and find out the docket and attorney information and inform them of your situation.