wanting to have sex but think I would be judged ...

Your questions and insecurities are normal for a girl your age. The truth is that most of the questions can't be answered. Every girl and every boy is different. They like different things, they are turned on by different things, they react differently, they mature at different ages, both physically and emotionally.

Having sex just because you want to is not really an option at your age. Sex is not just another tick mark on a check list. It comes with responsibility and often considerable emotional involvement. So your first aim should be to learn how to be around boys and develop a relationship with them, mostly a casual friendly relationship, but sometimes a romantic or sexual relationship with that special boy that just does something for you. Such a boy will not judge you, but accept you for the wonderful and unique person you are.

It also sounds like you have some body image and self confidence issues. A sexual relationship works best between two equal partners. It is important that you deal with your issues. It is often a false perception causing it, and it is not based on reality. And if you really are overweight, now is the time to do something about it.

I really think you should speak to your mom about your feelings. She is there to support and help you. Do not become sexually active just because your friends are, or you think it is time. The one thing most women say when they are asked about their first sexual experiences are that they wish they waited a bit longer.

You can also use the time to learn about your body and fertility now. If you have not done so yet, take a mirror, lock your door and look at yourself. Explore and identify all your parts. That knowledge is invaluable, especially since you get to do this while still a virgin. If you really need some sexual contact to deal with your urges, learn to masturbate. It is normal and natural, and will teach you a lot about your body and sexuality.

Best of luck!