For some people it's not as easy, and for me it wasn't always a walk in the park. It took awhile for people to understand and accept me as I was in school, because no matter what they said it wasn't going to make me perfect. There would always be something, someone didn't like. Anyways, I had to grow tougher skin and eventually I did. Now, to my knowledge I know that there are ways you can be confident and there isn't a true guide but it can be done.
It starts with you being happy. Are you happy? You don't need to change the way you dress or anything to outrageous, being confident is about embracing who you are.
A support system, someone who will be by your side no matter the path you choose, my family and friends were there for me and I'm grateful--because of them I'd like to believe they helped me through the trying times of middle school and high school. I can't speak for you or anyone's experience, I can only tell you about mine. Music, helped me find an understanding because there was always a song that I could relate to. Have mini concerts in your room, it doesn't matter...just enjoy yourself.
I have a saying: "Stay Strong, Move On, Stay True, Be You." I'll tell you what it means to me. There is always gonna be someone that doesn't want to see you happy (Sad but true.) You have to take a step back, smile in their direction, and move forward. Don't lose site of who you are just to make someone else feel better. Do. Not. Give. Them Power. Lastly Be yourself. It's the best version of you.
1. Be happy
2. A support system
3. An outlet such as music
4. Be yourself
So, no, there isn't a concrete guide on being confident and that's not what this post is, but there are a lot of tips and you can build from there. I hope this helps you build confidence (Demi Lovato has a great song my lady anthem.) Most of all, I hope you're having fun and being happy this summer.