How do I talk to a guy help!!

So I'm talking to a guy who goes to my school but we're talking through Snapchat and in my school uniform I look ugly or atkeast I think I do and so I'm not confident at school how do I talk to him at school and be confident I am confident outside of school because I know I'm beautiful but at school that knowing of my being gorgeous dissapears d I become not confident and I know that everyone is just gonna day be yourself but I can't helo the self doubt at school and I really want to talk to him in person you know? I hope this makes sense please help me. Oh and at a party he kept in leaning in and got a glow stick down my bra and wanted a kiss for it but I pulled away a lot but I really wish I kissed him, if I talk to him in person for a few more months or weeks imthinking of asking him to go somewhere together what do you guys think?