What are good fat burning workouts and diets?

i have some fat in my body (arms,belly,butt and legs)and i really want to get rid of it! do you think running(cardio) helps?like for my whole body?b/c i want to look good for the summer and what bother's me is when i where a long sleeve shirt and my upper arms feel so TIGHT but my stomach doesn't. etc.. and i know you can't spot reduce..and i'm also only a teenagerr.. and i also need a proper diet.. thanks if you answerr(: