You should consult counsel as quickly as possible. You may have the option to delay your eviction for quite some time, several months is possible, but you must act in a timely fashion as soon as you receive notice that the new private owner or the new bank-owner of the property is proceeding with an eviction action against you. You have no obligation to respond to a verbal demand that you vacate the property, and you have the right to require that whoever the new owner is proceed with proper court processes to obtain possession of the real property.

Consult experienced legal counsel quickly.

Owners don't have the same rights as tenants with unexpired leases. As far as I know, the buyer at a foreclosure sale, whether it is the lender or a third party, has the right of possession as soon as the trustee's deed is recorded. At the point the new owner first obtains the right of possession, your possession becomes (or became) unlawful, and the new owner can then begin the eviction process, which starts with a 3-day notice, followed by service of a summons and complaint for unlawful detainer, and ends a few weeks later when the sheriff arrives to assist you out of possession.

Since more than a month has passed and you (apparently, at least) haven't been served with anything, I'd suggest that you at least try to find out what happened at the 9/16 foreclosure auction by going to the county recorder's office and obtaining a copy of the trustee's deed. If there isn't one on file, maybe the sale didn't take place.

Step one is to get missing information, Sounds like you're now living in someone else's house, and you should find out whose. If the buyer is an investor, they may be willing to rent to you for a while.

Many evictions are delayed because the lenders and buyers are too busy to deal with it on the spot and they are prioritizing by acting on problem properties first. Your time will come.