
Drive the trim version with the powertrain and options you want to buy. Spend at least 30 to 45 minutes in each car and drive in a variety of road conditions. Even small variations in such things as seat comfort and ergonomics can make a big difference in how well the car "fits" you.
Tell the salesperson that you're there only to drive and compare cars and you'll decide which to buy later. Don't negotiate the price at this stage. That should reduce the sales pressure during your test drive.
Our car buyers are often asked for Social Security numbers, even when they're not financing. Unless you're applying for a loan, don't give it, and don't sign anything that lets a dealer run a credit check. It can affect your credit score.