It is my first time to sell a used car to a private party

A potential buyer will come to my residence place to see my 2002 Chevy Prizm for sale. Since it is my first time to do this, I would really appreciate your advise/tips.

1. If she wants to test-drive the car, should I let her drive alone or I sit in a passage seat?
2. Is it typical to let potential buyers come to seller's residence place (e.g., a house) to see the car for sale? Should I meet them, say, in a parking lot of shopping mall?
3. If she decides to buy the car after negotiation, how much should I ask for a deposit to hold the car? The car price is in the range of $4500 - $5000.
4. What is the typical form of final payment: cash, cashier check, or certified check? Which form is the best? I assume I cannot accept personal check.

Thank you very much.