You can usually play volleyball for your school, but if you want to play outside of school, you may have troubles finding a league to play for. There are probably a couple leagues at least in Las Vegas Nevada, but how close to the city you're in will vary. I mean if you really wanted to play, you could drive the extra distance to go there or you may have to convince your parents to take you if you can't drive.
It's easy to find volleyball leagues in Las Vegas or any city really; just look in the newspaper, watch for flyers at school or posted around the city. Also, if you want to play beach, volleyball leagues in Las Vegas you can go to is the Centennial Hills Sand Volleyball Complex. This is a place hasn't been up too long and it is where you will have to register your own teams to play.
However, if you're unable find volleyball leagues in Las Vegas, and you don't want to try another sport or drive, you need to keep your skills up for the following school year. You could do some volleyball drills if you had the place for it and if you were a setter, you may want to try going to some volleyball setter camps on the off season.