You can tell a boy that you like him directly without beating around the bush. Another way to tell a boy that you like him is by giving him a few hints like smiling at him when he looks at you and talking to him as much as you can. You can also text or email him, or you can use a friend to tell him.
just be friends with him for a long time. & smile at his jokes. get to know how he is first alot befor you try to be his girlfriend. just be yourself dont try to be like something/someone else. write him a note maybe.