How do you cast the furthest with a pinnacle ultra balance baitcast combo. when i turn the little grey nob on the side, the reel spins to fast and creates a backlash.

You're talking about the brake, right? For sidearm or overhead casting, you'll generally want to adjust the brake so the lure just barely falls on its own when your thumb is off the spool. That will help a ton with the backlash. If you're flipping / pitching, you'll want the brake pretty much off.

That's the spool tension knob.

Hootie

what does the spool tension do

Puts tension on the spool. Start by loosening the spool tension knob. The re tighten it until there is no side to side wobble in the spool. Turn the brakes up to half way. Hold the rod 90 degree and adjust the spool tension do your bait slowly drops to the ground. If your just starting out try to get it so when the bait hits the ground the spool no longer spins and then give it a try. As you get better loosen the brakes a bit until you become proficient.

I take it you haven't read the 2 stickies at the top.  This: http://www.bassresource.com/bass-fishing-forums/topic/92295-how-to-set-up-a-baitcaster/ and this: http://www.bassresource.com/bass-fishing-forums/topic/106413-how-to-cast-a-baitcaster/

 

Lots of good information in the 2 threads.  Also search for videos on setting up and casting with a casting reel.

 

You are at an ideal age to learn.  Give yourself some time.  Practice.......a lot.  Do not try for long distance at first.  It will come with time.  Learn to use the side arm roll cast.  It will help eliminate backlashes because it is easier to keep a constant load on the rod.

Kevin, you first need to understand why a bait caster backlashes. It backlashes because the spool is spinning faster that than your lure can pull the line out. To overcome this, you need to adjust your brake setting kinda tight if you are a beginner and you need to use a lure that is aerodynamic and one that is in the upper weight range of your rod. For example, if you are using a 7' Medium Heavy/Fast rod that has a lure range of 1/4oz to 3/4oz, you should be using a lure that weighs closer to 3/4oz. The heavier aerodynamic lure makes casting for a beginner easier.