Hi,
By all means, say 'yes!' Going to a dance or hanging out with someone is being friends. However, if he tries to kiss you, then you can draw the line if you want. You can say something like - "You know, xxx I really appreciate you inviting me to the dance and I had fun; but, I really want to keep our relationship at the friends level for now. I like you very much as a friend, but I am not ready for a boyfriend." Who knows you might change your mind again - after the dance. Be calm and by all means, be kind. Best Wishes!