I really need to lose weight!?!

I get that you want to lose weight - I felt exactly the same way when I was twelve. And I'm sure you'll probably get some responses that say you should absolutely NOT go on a diet, but if you feel that you'll be more confident if you lost weight, then I'd say there is no harm with going on a healthy diet. Don't start thinking that you're overweight, though - you're definitely not!
Now, unless you're already doing so, start by exercising every day. Yoga is great for that, but it can be expensive and time-consuming; a better alternative might be just going for a ten-minute run when you get home from school. This might be hard at first if you're not used to it, but it will pay off.
As for dieting, try to identify if - and when - you overeat. I have noticed that I often eat too much when I'm tired or stressed. It might be the same for you, or you could have very different "triggers".
Eat regular meals and be sure to eat when you're hungry instead of putting it off. Starving yourself will just make you eat more later.
Stick to "raw" foods like veggies, fruit, whole grains, yogurt, etc. Try to avoid junk food as much as you can.
One last thing: I know you don't want to hear this, but you ARE 12... so be careful! You're young, and your weight is perfectly healthy. Please don't take any dieting/weight loss strategy too seriously.

the 6:30 gets up early 5 minutes,
molds small waist 6:50 in the morning a water,
expulsion of toxin losing weight 7:00 to start from the breakfast to promote metabolism the 7:30 choice to suit own underwear 9:00 to sit down do not curl upwards one leg on the other 10:00 to rest, makes pate movement the 11:30 before meals to drink the cup water, increases the full abdomen to feel the 12:00 lunch to want the nutrition richly, balanced 12:30 food latter a half hour not to sit 14:00 not to wait only then to drink water thirstily 15:30 to replace chocolate with the apple the 17:00 work-to-home peak hour, little sits two station vehicle the 18:00 dinner to eat ahead of time, refuses to fry in oil the 19:00 to put on the losing weight shoes to do The housework, molds US leg nearby the 20:00 to watch the television, movement 22:00 fragrant smokes bath Shu Yayou losing weight the 23:00 suitable sleep is most economical loses weight method

I don't really have a detailed weight loss plan but i would recommend you eating a lot of fruit. Going on long walks. Get a lot of exercise! I don't recommend going on a serious diet because your kinda young.

24 is a great number to be at your age. my BMI is 26 and im only a couple years older than you. if i can handle my bmi you can handle yours and i wish tht i could be 139 instead of 168.