Worry less about velocity and more about the three other things that are more important:
1. Command: hitting your spots, low, high, in, out.
2. Change of speed: throw a 4 seam, two seam, and a change up for now. Get those pitches down with control.
3. Movement. That is to say, ball movement. Your 4 seam will be 'straighter', the two seam will dip or move away from a righthanded batter if you're righthanded, and your change up will drop like a rock!
Velocity is only the fourth most important thing about pitching, especially at your age!