How do you ask a girl out if you dont know if she likes you or not and you dont want to look dumb?

tell her that she is the light of your world and mean it!

To add to that statement, simply tell her how you feel. If she views your honesty as "dumb," then clearly she is not worth your time to begin with. A girl who is mature will either put you down gently or - the best scenario - will be flattered and agree to date.