Answer:
Step-by-step explanation:
This is not exactly Physics but here you go:
What did you find most challenging about mastering this skill? Why?
Setting is the most challenging because it requires many different techniques. There is a designated setter in competition games exactly because it is the most challenging position. It also requires lot of practices with your teammates.
What did you find easiest about mastering this skill? Why?
Serving is the easiest because you literally have the ball in your hand when you serve. Now it is not as easy if you want to make a serve that is difficult to receive. When a player fails to serve, it is usually not because it is tough but rather the player is trying to make a hard or spinning serve.
I am not particularly athletic and above is from a little play time I have had with volley ball in high school.