Is this Shoulder workout Good for a teenager?

[Ergis]

That is my shoulder workout. I do it once a week. Is this enough for an teenager who has some experience in weight training?

Warm up:
Military press 2x15 (5kg)

WorkOut:
Military Press 2x12 (8kg)
Shrugs 3x15 (8kg)
Side raises 3x12 (5kg)
Rear delt raises 3x12 (5kg)

Any tips would be appreciated!