My classmates said that I waited for a while and was bored. Although my academic performance is very good, how can I correct it?

Your good grades are an advantage. Don't feel inferior. Generally, people with good grades are more confident. You can talk about your hobbies with others, learn about your friends' hobbies and establish the same topic. Also, maybe your stupidity will make you calm down and study hard. So keep it in good shape. Start (a disease)