You have a nice serve kid. Leave your left hand up longer, , really relax your wrist during your takeback and go for more trunk/shoulder turn. Trunk/shoulder turn can be enhanced by pretending you're elbowing someone in their head with your right elbow in the trophy position. No criticism here just minor tweak suggestions. Toss a little more in front (provided these are first serves). You have a good flowing motion, knee bend and get your left hip nicely pointed forward over the baseline while in the kneedend.
Hit 100 serves in practice everyday and call me in the morning.
Good luck keep working at it everyday.