Draft-legal triathlon is not like the local races you might be familiar with. There are different equipment requirements for the bike, and the swim becomes more important because it determines what bike group you're riding in. In-person practices, therefore, focus primarily on bike handling and swim technique as well as transitions. Volume training is left to the athletes with individualized workouts provided by the coach.
Here is how USAT describes youth and junior draft-legal athletes: "The highest-caliber juniors compete in draft-legal triathlons, called Junior Elite Cups. These sprint distance races mimic the ITU World Triathlon Series and Olympic format of racing by using multi-lap courses and fast flowing transition zones. Junior Elite Cups serve as qualifiers for the USAT Junior Elite National Championship. These athletes have above-average swim skills, the ability to ride in a peloton, and a strong run off the bike."
Draft-legal triathlon encompasses two age groups: youth, ages 13 - 15; and junior, ages 16 - 19.
The youth races consist of a 375 m swim, a 10k bike, and a 2.5k run; the junior races a 750 m swim, a 20k bike, and a 5k run.
The distances of draft-legal elite races consist of multiple laps. For youth races, a one lap swim, a two lap bike, and a one lap run. For junior races, a two lap swim, a four lap bike, and a two lap run. If a racer is lapped, i.e. if the lead racer catches an athlete at the back of the pack, that caught racer is removed from the race (this generally only happens in the bike leg of junior races; it is rare for it to happen elsewhere).
The draft-legal season stretches from March to early August. The goal is to qualify for Nationals, held the first weekend of August outside of Cincinnati, OH. To qualify, racers must finish in the top 17 of one of the four qualifying races; those that have already qualified don't count toward the top 17 in a subsequent race, so top 17 refers to the top 17 unqualified racers.