It is very dependent on how much time the season last for you. Getting into "race shape" can mean peak racing or it can mean some race pace work has been done. Since they aren't already in shape you need to first work on their aerobic "base" fitness. So a run and some strides (4-6 x 100m) to start. You can toss some harder workouts in there like a ladder of 1k, 800, 600, 400, 200 so they can get a little feel for pace, but 2 harder workouts is plenty.
800/milers/2 milers aren't always super easy to identify for kids only 14-17. Not all of them are fully developed to classify a best event. So a lot of the work should include all of them running together and vibing off of each other. A workout with a mixture of paces will work well to see who is good at what.
A month plan for beginning of track season would be as follows:
Sun: Long run
Mon: easy run/strides (core work/drills)
Tue: Workout or race
Wed. easy run/strides
Thu: tempo run or workout.
Fri. easy run/strides
sat. Race or workout
This would just be a progression of intensity/volume throughout the season as the get fit. I think its fine to use mostly the same workouts for the 3200/miler/800m guys, but just switch things up a bit at the end of the workout. An example is 800, 600, 400 all together, then 2 milers do 1k,800,600. While the 800/milers do 600,400,200,200,200. Also the volume for the easy runs should vary from 2 milers down to 800 guys.