I been divorced for over ten years but can't locate my ex nor the papers nor the place where he filed which I don't know where I have his last name still can I still get married with his last name?

You might want to go on one of those sites where public records are available and do a search on yourself. It should show up in the search.

Depends on where you are getting married, and what name is on your drivers license or other official ID.

Each state in the US has different rules