No you shouldn't be going with a girl 3 years younger then you, this gap in time isn't as important then say your 20s but when your teens it's a big difference. I see WAY too many 13, 14, 15 year old girls with 18, 19, 20 year olds, and it's not a coincidence that the pregnancy rate for underage teens is higher then ever.
Wait for college, you'll get alot of hot chicks your age, you will drink and fuck alot during this time, just be patient.