So far you have gotten a lot of good general answers, I will try with a few more specifics.
Try looking at your situation as a chance to do something entirely new.
To find out what is something that would be right for you, take some time and write down all the things you really enjoy doing.
Then make a list of all the things you think would be really great to know how to do.
Make a list of the places you like to go to, or would like to go to.
Think of the people you would most like to be like. What do they do?
Think of the people you have met that are the most interesting, what makes them so interesting?
What subject would you like to be an “expert” in? At your age, if you started really learning about something that interests you now, you could become quite knowledgeble about that subject in a few years, and really have an edge later in life when looking for a job you would like. If you know what you would like to do for a living, or what industry you think you would like to work in, get with some people who do that and ask then what you might start doing now so you will be ready to do that later.
My niece wanted a career in the music industry. When she was your age she volunteered at a local radio station and learned a lot about how they operated. She got to meet all the local celebrities and helped put on fundraisers. When she graduates, she knows she can get a job there if she wants. But she also made many other contacts and has lots of other options as well.
Once you find something to do, the making friends part will come naturally. You will be involved in something and meet others that share that same interest. It will be a whole new group of people you wouldn’t otherwise have met. You may still have the same group of friends at school or in your neighborhood, but you will be busy learning something new and won’t have the need to hang around all the time with the crowd you now have. Learning something new is a great way to build confidence, and will help you in the future to stand up for what you believe is right.
Here are some of the things I did to meet new people. These particular things might not be of interest to you, but I am going to list them because they might make you think of something related that you would like.
Take a photography class. You will get assignments each week which will get you out meeting new people. I would go to a park and practice taking pictures of people doing things; kids playing basketball, people’s dogs, people launching a boat in the water etc. I would approach the people and tell them I was in a photography class, and ask if they minded me taking pictures of what they were doing. Everyone said they didn’t mind, and it was a fun way to meet people. I found when I have a camera, even if I am alone, I don’t feel alone. It gives me an excuse to go places and do things I might not have otherwise done.
Dog agility training. I don’t know if you already have a dog, you might not and that might be out of the question, but maybe you can borrow someone’s dog. The local shelter here looks for people who will help to socialize dogs and need people who can come and take a dog out for a day. I took my dog to learn to run an agility course. The other people in the class were all ages, and a lot of fun. I had to spend quite a bit of time working with my dog, and she never was very good, but I am really glad I did it.
Volunteer at a place that interests you. My sister in law loves going to plays, so she volunteers at a local theater as an usher. She works several times a month and gets to see all the plays for free. Another friend loves the zoo, she volunteers there, and now goes with groups of people who bring animals to places like old folks homes and educates people about the animals.
Where I walk my dog, there is a radio controlled airplane runway. Every time I go out I see people of all ages flying those planes. They are really good at it, and it looks like they have a lot of fun doing it. Same with radio controlled boats. There is a large pond near my house and I often see kids out there having races with their boats. Some of the kids said they build their own boats and sell them to others to make money to buy more boats.
If you like to sing or act, there are usually places that put on plays or choruses that travel around. I had no desire to be on stage, but I did volunteer to help put on a community play. I did the make-up for the actors, but there were others there who helped build the sets, did the lighting, sound etc. That could be a way to learn a new skill as well as meet people and have some fun.
So a start might be to think about what you would like to be doing in five years. What skills and abilities would you like to have? What people would you like to be spending time with? What things on your list of interests would you like to be involved in? What can you do now to work towards being that guy you would like to be in five years?
Use the bad incident that happened today as a turning point start working on being the START you want to be in the future. The making new friends part will come easy once you start doing some new things.