BMX as a sport is on the rise in the US. The tracks , the bmx bikes, the speed the comradery.
BMX tracks can be found all over the country. California was one of the starting grounds and has a high concentration of track. But looking on the USA BMX site you can find a track near you.
BMX bikes no doubt can get expensive. Do not let this deter you from getting started any bike will do to get started and check out your local track. As you progress in your racing so will your bike and your need to upgrade your bike and parts.
BMX racing is for all ages and sexes. I very enjoy seeing whole families enjoying the races and supporting each other. Little ones start as young as 2 on strider bikes, and on the other hand there are 50 plus years out there racing and practicing with their children.