What if you like a girl in your class who is occasionally smiling and sometimes just doesnt want to talk to u?

I have a problem with that girl talking to one of her friends while me interrupting or adding on cause im a shy person and since i have like 13 more full days of school left, How can i get her to notice me and get her to talk to me, and how can a person whose shy, start a conversation with a girl intimately, and not become sweaty or lose your words when in a long conversation?What if you like a girl in your class who is occasionally smiling and sometimes just doesnt want to talk to u?
just keep telling yourself to focus and stay calm,

stay calm!!! don't let yourself get nervous. and if you start to just whip yourself back to being calm again. just keep yourself together if you really put your mind to it you can do it