In this forum I realise how different cultures are, while for some people dating at 18 it's too early, in other countries, such as mine, you are considered an alien if you are 18 and still have not had a boyfriend or girlfriend.
I don't think you should worry so much about what your parents will think if you have a date. Parents always want their children to be happy, but they must realise that you must learn to take your own decisions. You might make mistakes, probably a lot of mistakes, but that is what growing up consists of.