new here

hi my name is matt i'm new-ish here in mfp. I'm not really sure on how to use myfitnesspal on how much i should eat and how much i should exercise. I'm looking for friends who can be my rival and also help or motivate me with my weight loss. i plan on losing 30-40 pounds. i'm 5'5 160-170 pounds ( in a week that's my weight, it goes up and down). Please add me as a friend