Idk what to doo

So I have liked this guy and he is in 9th grade. And we been making eye contact with him a lot and I always see him looking and me. But the school year is almost over and idk if I should go ask for his number bc he is more a popular guy and I am really nervous and idk if he likes me back but I have really strong feelings for him and I my mom said I should write him a note but i think that's a little old school. I don't know what to do please help 👍👍👍👍👍👍👍👍👍👍👍