If you are getting that many "professional overuns" - aka backlashes, you might try tightening the spool tension knob, and also check to see if you have any anti-backlash breaks. I'm not familiar with your reel, but many use magnets that you can adjust to have more or less drag on the spool.
To adjust the spool tension correctly, you should be able to depress the thumb bar, dip the tip and raise it again, and your lure should fall slowly to the ground, with the spool stopping once the lure is on the floor. You won't get as much distance, but you can loosen it up more as you get better.
Also, as you progress with your casting, you will learn to use your thump to "thumb" the spool to slow the speed of revolution.
Finally, try not casting so hard. To begin with, you need most of the action of casting coming from your wrist. Once you have that down, then you can begin adding extra arm movement, and even two handed casting.
Again, congratulations and good luck. My mom and dad started all of us out on baitcasters. We tightlined the Ohio river. We had to pick out our own backlashes. We started our own casting around 5 years old. Mom and dad would not even entertain the idea of a Zebco for one of us... LOL Now I'm glad, then not so much!!!!!
Danny