To serve normally in volleyball is easy but the main problem arises when the question comes to overhand serve.Here are a few tips which will help beginners to learn overhand serve:-
Step 1 :
While standing to serve in volleyball place your non-dominant foot a little ahead of your dominant foot.
Step 2 :

Hold the ball at 90 degree from your shoulder and keep your hand flexible.Now place your dominant hand stiff and next to your ear.
Step 3:

Now throw the ball near your dominant hand and hit the ball using your palm.
While hitting the ball take a step forward to exert more pressure on the ball so that it goes faster.
*These are some easy steps to learn to serve.
Recap:

Hope it was helpful to you.
Step 1 :
While standing to serve in volleyball place your non-dominant foot a little ahead of your dominant foot.
Step 2 :
Hold the ball at 90 degree from your shoulder and keep your hand flexible.Now place your dominant hand stiff and next to your ear.
Step 3:
Now throw the ball near your dominant hand and hit the ball using your palm.
While hitting the ball take a step forward to exert more pressure on the ball so that it goes faster.
*These are some easy steps to learn to serve.
Recap:
Hope it was helpful to you.