In the lower end of numbers (like 9th Street) is more where the surfing section is. In the 17th-19th Street area is more of where the restaurants/shops are (and where more of the people are). In the higher 20's there are a lot of hotels (although hotels line pretty much all of "the strip") and less people actually on the beach and on the Boardwalk. The Boardwalk is a few miles long so it's easy to access all of the areas. Parking is EXPENSIVE during the summer months (especially holidays). There's a city parking lot on Pacific Ave. which is right off of Interstate, you just turn right on to Pacific and it's the next stoplight, but it fills up fast during the day (the road that runs along the restaurants/shops is Atlantic Ave. and very busy and the most expensive places to park). Pacific runs pretty much parallel to Atlantic (while in the "beach" area anyways) and parking is usually cheaper here.
During the night/evening they have performers like singers, jugglers, magicians set up along Atlantic Ave. for free which is pretty entertaining and there are several stages along the Boardwalk that typically have free concerts on the weekends or during festivals. Virginia Beach has really tried to maintain a family friendly beach area so you'll see signs for no loud music, cursing, cops on horses, bicycles, cars, on foot, etc.
Also, if you wanted to there's a nice calm beach at First Landing State Park which is only a few miles from VA Beach. It costs about $5 to park but it's better than the cost of parking at VA Beach.