its not all its led up to be, the hours are long and tiring, and straight away you wont be asked to be carting in a tractor, i'm 17 now, had my tractor license since april 2010, only last month started carting for the farm i work on, i work 10 hours a day term time for £6 an hour, last year it was £5 an hour for the same, when you start you'll be on the crappy jobs, have to work your way up, its either in you or not, other than that i wish you the best luck pursuing your future, and just stick at it,
All the Best
Trev