I agree with just about everyone here.............. you get a chance @ shooting a jake and he's your first turkey, you kill him and be proud!!
My first turkey was a jake as well and I killed one more when me and a buddy had a chance to double up.
Most guys switch to shooting mature birds the more they hunt...... its just a natural progression. But to kill your first one, two or even three, don't worry about it. Shoot whatever makes you happy.