Well it's good to start early but not too seriously. I guess that the start of my cycling interest was cycling 10 km each way to high school at 12-13 years of age. By age 14-15 I was riding 15km out, a rest and then 15 km back after school and I think I was 15 when I built up a lightweight racing bike and was competing in club races.
Nothing wrong with organized training but keep it fun.
Regards, Anthony