New to my fitness. Looking to get in shape

Hi there I'm a 6'0 165lbs 18 year old male who is looking to get into better shape. I don't want to lose weight but instead lose fat and gain more muscle. Hopefully tracking my diet and exercise can help me achieve this. Fitness goals include 20 pull ups, 100 sit ups in 2 mins and a 20 min 3 mile run. Right now I'm at 11 pull ups 65 sit ups and a 24 min run.