oh k I am 14 years old I'm 5'7" and I weigh about 140 pounds or a little more. am I big fer my age and I do see chunckyness on me. so am I gaining to much weight?

and I eat a lot. its habit I see food and if its good I WANT IT soo bad so if I should cut back on the proportion of food I eat a day what should I eat for one day? and how much? and how do I stop myself from eatting everything I see thats good?