I bought the clippers, totally messed up his hair trying to do a "lion cut". Now that its been a few weeks his hair is just all different lengths and he looks crazy,

lol. what would be the closest I could cut it without him looking like a complete mess? lol. Oh and I forgot he is a little 4 month old puppy. He can't go to a groomer until he has all his shots and he has had kennel cough since I bought him, so he wont be going to groomer anytime soon....any suggestions would be GREAT.
Thank You SOOOO much