how to be more confident?

I've always wanted to try out for my high school track team since it was a sport I've always loved since elementary school. I did the sport in elemtary school, but never middle school since my mom told me that I should be going to tutorings instead since she said that sports won't get me anywhere in life. I'm a junior in high school now and I've always wanted to try out since freshmen year, but I just can't go alone and no one wants to run with me for fun at least and I'm too shy to go by myself.
I barely have any confidence to do most things alone, but this year I really want to try track but it makes me cry since I'm too scared to and it makes me ashamed of myself. How do I make myself more conifident? I have tried taking it before, since people say faking it could make it turn into something real, but 3 years later there is no progress. What do I do? Please help