Since you are a vegetarian, you should be eating beans and other sources of protein. You also need a good source of vitamin B12 to keep your energy up.
You might just need to cut your portion sizes.
Make sure you cut out all junk foods, such as candy, chips, sodas, etc. Cutting those out could be enough to allow you to lose some weight.
I don't think it's necessary to join a gym. At 15, you should be getting a lot of exercise in your PE classes or other sports, if you are in any.
Walking/jogging are both good exercise; aim for 30 minutes/day 3 days/week to start and try to increase as you go. Interval training is good and be sure to add some strength training. For something different, you might try some yoga, too.
well I can help if you're willing to change your diet and habits - I'm a former bodybuilder and national-level powerlifter and I know a thing or two about nutrition. what u need to do is start upping your protein intake and reduce your carbs - as a vegetarian you will want to incorporate more egg whites and legumes and fish - I realize that vegetarians are making a change because of strong values and I appreciate your commitment - in fact there are a lot of vegetarian bodybuilders out there - google vegetarian bodybuilding and u will get a lot of good links to assist with your diet. now the second mist important thing is to start a fitness regime. probably at 15 you have a very high metabolism and the energy to work into a good training work out - try starting off with alternating a walk and jog for 20 minutes every other day - I like running from my house and I will walk part way to get used to it - I always set s goal like "I'm going to run to that place without stopping" then I do it but reward myself with a small walk to catch my breath - then resume running again. I try to go a bit further each time, I find running before breakfast gives the best results but I can't always do that so I run right after work when I get home - take your iPod and laid it with tons of kick *** tunes to get u going. also - join the local gym and lift weights. good for your physique as well as your health. at a body weight of only 117 lbs I deadlifted 303lbs and did 270lbs squats when I was competing - I hope this info helps you - best of care :)