Quote Originally Posted by JBizzlebone

It's not necessary but makes your experience a lot safer. As stated above, NASA is a great avenue as you can opt to have an instructor in the car with you teaching you what you should and shouldn't be doing. They'll time your laps to see if you're getting better and give you tips on how to be faster. It's an incredible experience and I think everyone should do it at least once.
NASA will never time laps in a HPDE session. It is strictly forbidden by the CCR. HPDE is an excellent way to learn how to drive on track, but it is NOT racing and thus not timed. The instructor should not be timing the students laps, either.