Learning how to respectfully kiss a girl is not that difficult. If you are not sure, you can just ask if you can kiss her. If she wants to kiss you, then either she will say yes or she will just kiss you. If she says no though, then that is where the respect really comes in to play. If she rejects your kiss it does not mean that she does not like you, it just means that she is uncomfortable.
And in the case where she may not actually like you, then you also need to respect that. Just say okay and let her know that there are no hard feelings. You do not want to start calling her names or being rude to her just because your feelings got hurt. You can also let her ask or kiss you. The social norms are not the same as they used to be. Girls can and often do make the first move.