I live in Oregon. The property I live on was just sold and the new owner wants me out. He hasn't asked for rent, just wants me to leave.
I've heard he can give me 24 hours to get out. My question is can he do that, or does he need to give me 30 days and an eviction notice, or what? Please help!

If you don't have a lease and you pay your rent monthly then he has to give you a written 30 day notice. If you haven't left within that time then he has to file a lawsuit to evict you.

If you have a written lease then he has to honor the balance of the term of the lease.