One month will not get you a six pack. You need to build the muscle. Go on a high protein diet, and eat two servings of carbs before you workout. Get a Pre workout booster. For abs sit on a stool with no back and put your legs straight out in front of you. Make sure there is something over but NOT under your feet. Lean as far back as you can and take ten seconds to do so, then come back up taking another ten seconds. Do not rush these or you will have misshapen abs.
Crunches for the uppers, alternate one crunch one five second three inch leg lift.
Get on a pull up bar, lift yourself so your chin is above the bar. Pick your knees up to your chest and bring them back down, now do the same thing but so you're in a sitting position. Repeat.
Sit ups while holding a five pound weight above your head straight up with both arms, take ten seconds for each rep.