how to make the most of prom time

Help her make plans. Prom is not just about the dance itself. The prom experience includes transportation, pictures, dinner, the after party, and more. Offer your assistance with the planning process to not only share ideas, but also to show you care.
Discuss whether you will be attending prom with a group or whether you two will be attending alone. Coordinating plans with a larger group requires more time and effort.
Decide the best time for pictures and dinner, and what time you plan to arrive at and leave from prom.

Plan your transportation. Decide whether you will be renting a limousine or whether you will be picking up your date in your vehicle. While you may be in love with your vehicle, your date may prefer a more romantic gesture like a limo (which can be quite pricey).
If you decide to drive your vehicle, be sure to put gas in the vehicle the day before to avoid running late.
Make sure you car is clear of clutter and both the interior and exterior are cleaned.
If you will be renting a limo, be aware that they are usually booked by the hour and most companies have a minimum number of hours for which you must reserve the vehicle.
Whatever form of transportation, make sure you exit the vehicle to retrieve your date and always hold the door for her or allow her to enter first.

Dress to impress. Girls usually put a lot of time and thought into their outfit and they expect their dates to look just as great as they do. Because prom is usually a black tie affair, be sure to dress formally and to be well groomed for the occasion.[1]
Wear a nice suit or tuxedo to make sure your dress is formal enough for the occasion.
Find out what color your date is wearing so you can coordinate small details like socks, ties, and pocket squares.
Pay close attention to your hygiene that night including showering, shaving, getting a fresh haircut, and using cologne (sparingly).