Are you friendly with anyone out of school? While school is a great place to meet new friends, its not the only place. Have any cousins or neighbors similar in age? On that note, a friend doesn’t even need to be from your class.
Maybe during one recess or lunch join a conversation. You don’t need to be the center of it, but stand close enough to say something and be part of it.
If you feel that recess and lunch is spent at your desk doing homework, ask a teacher or your principal if theres something extra-curricular for you to be involved in. Better yet, come up with something. A gemach, chessed project etc. If you feel comfortable and you’re school has an elementary in the same building, maybe you can tutor someone in a younger grade who needs help.
Hatzlacha