Looking at the needle side of the carb, the high is on the left (towards the front) and the low is on the right (to the rear)
Close your needles (clockwise) until they stop. don't crank them down, just lightly seat them. Turn the Low needle out 1.25-1.5 turns. Turn the High needle out 1.5-2 turns. I would recommend you go to the higher for breaking in the engine, never hurts to run rich and have a little extra oil rather than run lean and mess the motor up. You may have to turn the idle up.
Before you run it, take the air filter off and double check the bolts under it that hold the carb to the base, mine were loose. Also while you have the filter off oil it. If you don't have filter oil, pick up a bottle, it will save your engine. Oil the INNER filter and leave the outer filter dry.
You want to heat cycle a new engine. Run it for 10 minutes then let it cool to outside temp (or so you can touch it without getting burned). Do this 3 times. Now start it back up and finish out your first tank, don't go over half throttle, you want the engine parts to seat properly.
Your second tank, you can get a little more crazy, but stay under 3/4 throttle. don't adjust the needles yet, finish out this tank and then let the engine cool.
Now that you are on your 3rd tank you can adjust the needles. You really shouldnt have to mess with them much from initial setting. If you do decide to play with them, turn them in SMALL incriments, 1/16th of a turn make a HUGE difference in these gasoline engines. Adjust the low needle first and then the high needle, I know it seems backwards, but the low needle always flows on these carbs, the high needle works from 1/3 throttle up.
If you need a new spark plug, get a NGK
CMR7H. Napa sells them for 4 bucks and they are WAY better than the Torch brand that King Motors uses.