Introducing...me!

[Steve M]

Dani,
Starting at your age, you have the opportunity to have a great career umpiring.

For advice - here's some that I've posted before
Keep a diary. List every unusual play/ruling and everything that you do not understand. After the game, spend time in your rule book and case book. Add the explanation to your diary.
You probably already have a good idea as to who the better umps are in your area. Watch them work every chance you get. Before the game, introduce yourself to them and let them know you're going to be watching them and that you'd like to talk to them later about their calls, timing, rulings, ...
Along these same lines, speak to a skilled umpire that you - and your parents - trust. Ask this skilled ump to be your mentor, to watch some of you games throughout the season and provide you with one ot two areas to cencentrate on each time. (I am of the opinion that you really can not work to improve more that one, maybe two areas in your game per game.)
Hang out some at this board - there are some really skilled folks here and the board is a registry-required board, so it's safe and not offensive for a younger person.
Study your rule book - several times each season.

These will keep you busy for a while - after more than 30 years, they keep me busy.

Steve M