Elviscat,
Like you, my father used to take me on the job with him.
When I was 13, all my friends were out playing football after school and I was in some building pulling wire and fishing walls.
You father knows you better than any of us and will most likely show you new things when he deems you ready to learn them.
The biggest thing I can tell you is that this is a huge trade that encompasses a lot of theory and material. The fact that you are getting off to an early start is fantastic but, never let your ego get away from you on the job.
I've been licensed for 15 years in two seperate states and I run into new things on the job everyday.
Listen to what your dad and other electricians on the job tell you. Their experience is invaluable and most of all, ASK QUESTIONS. If you don't know how to do something, it's always better to ask than to make a mistake just because you were afraid of looking bad on the job.
The best advice I can give you at your age is to pay attention in algebra class.
You will use it alot in this trade.
Once you have a good algebra base, study ohms law and electrical theory.
These are things you won't learn on the job site.