I ran cross country in highschool.
Just like other sports they practice every day, weights, runnng obviously, and ususally some things to spice it up.
When you go to practice make sure to bring a gym bag, with some shorts, some pants (incase it rains or gets cold), a lot of water, sometimes getting sweat bands for your head and arm is nice if you sweat a lot. It really is fun and you make a lot of great friends. The amount you run is totally depending on you! Just like any sport, all coaches are different and will have different practice times. Most races are usually 5k (3.1 miles) but some are more and some are less. Make sure you wear some running shoes, and I always wore compression shorts, they help a lot, not only keeping your cool but keeping your shorts from riding up! XD Good luck! It's tons of fun!