I want to increase my vertical leap fast!!

Right now, I don’t think my tennis coach is working us that hard: suicides (touch every line)-about 5 reps, 3 sets (10 sec breaks in between reps)
crab walks-across court up and down-1 rep, 2 sets
squat jumps-10 reps, 1 set
run up to the net, then run backwards-5 reps, 3 sets
Are there any other good tennis conditioning drills that anyone knows?

I want to be able to dunk and jump further. What training methods should i do? I can’t afford buying training kits or weights

I am 5’7 and am 16 and at the beginning of my last track season my vertical was 21 inches (that was off of one foot though cause i was way more used to jumping off of one foot). Is 21 for a vertical good, bad, average?
also i have been playing a lot of volleyball this summer and was wonderting if i tried my vertical again and jumped off of 2 feet if that would increase my jump?
thanks

i want to be able to jump real high because im not that tall so what stretches can i do to make me jump taller and how many times a night should i do them? also, what stretches will help me grow taller?