How do I communicate with people?

I wanna know to communicate with people. I don't have friends or close friends, I can eat alone like a pro, thanks to a group project, but I can't communicate with my classmates and I got no problem doing things by myself, but I really wanted to make friends and have meaningful relationships, but I always keep to myself and I can't talk to anyone, not even my classmates. I think I need to communicate during class to improve my grades and I can't even do that, I can express myself in writing, but I can't even talk to my classmates in class. It really sucks and I'm jealous of how some people can communicate and make friends so easily, like, how do I get that? I don't even know what to do.