I know quite a few people, particularly girls, in the outer world feel very shy and awkward around their classmates, especially guys but there is a way to bring this awkwardness to an end. Carry on reading and aspire to become a confident individual as confidence is key.
As for the start, there is a need to realise that by being shy and the "last one to speak up" you'll not get too far and you probably don't want that because hey, when and how will people uncover your terrific personality if you stay in the corner by yourself ? Before staying out of a conversation and acting shy think about all of those horrible consequences. You don't want to face the nightmare of being a ghost.
After you have secured the previous thought in your mind think about the things and possibly people who don't allow you to be confident. If you're insecure about your looks throw some make up on and there is no need to purchase anything super expensive: simply buy good skincare products and maybe a concealer together with a mascara , a blush, a brow brush and a lip gloss of a cute shade. If you don't like your body ...Stop it....Confident individuals love themselves and you need to learn how to as well. On the other hand try to work out a couple of days a week and cut down on all that chocolate because you might find it tasty now but 15 years later you're quite likely to regret it. If a person makes you feel insecure and constantly oppresses you get rid of them because you don't want to keep a negativity provoker in your life. In a nutshell: LOVE YOURSELF AND PEOPLE WILL START LOVING YOU.
Last but not least, speak up! There is no need to hide from the world even if everyone thinks you're super weird, in fact it's good to be strange because your unique personality is what defines you regardless of what others think. Of course there is no need to be rude to anybody and too self confident but why feel awkward about your personality if it's amazing?
Guys, if you want to start being confident you need to believe in yourself as if you won't do so no one else will. Also, always remember this amazing quote - "Fake it until you make it".