As somebody who has been a vegetarian for over a year (healthy, athletic, best shape of my life, etc), I guess I should give some advice:
First and foremost, congrats! It's an admirable choice, as long as it is your own. Just remember to not rub it into people's faces, as that tends to piss them off.
Second, take vitamin supplements. It is possible to get enough iron from beans, but it's a bit challenging to balance your diet.
Third, don't believe this crap about needing meat in your diet. Plant proteins are no different from animal proteins, and you only need 8 amino acids from those anyway (assuming you're no longer a toddler). Beans/tofu/cottage cheese are your friend here
Fourth, give tofu a shot. I can't expect you to love it, but it is extremely versatile if you know how to cook with it. Plus it's nutritious and all that...
Fifth, being a vegetarian does not mean automatic fitness. Get some exercise...