It is enjoyable to almost anyone. My husband and I go every year from Kansas City, MO. We always stay in a hotel (which is pricey that weekend-but worth it). We find the race to be good clean fun.
If you're into more of a party atmosphere, I would recommend camping out in the lots surronding IMS (Indianapolis Motor Speedway)...there seems to be alot of "fun" going on there:). Some people who live near the track also will "rent" you a spot on their lawn to put up a tent. You can camp out right in their front yard.
Before the race, all are welcome on the inside of the track near the pits for free. You can get pretty close to the cars and drivers. It is a very fan-friendly race.
There are all walks of life at the race. Young, old, black, white...everyone enjoys it.
If you can't make it that weekend, you can always go any weekend during the month of May....practice and qualifications take place. It is much more affordable.
I would say that IMS is definitely worth seeing once in your life. It is amazing.
Feel free to contact me through answers if you have anymore questions. Take care---have a fun safe trip!