I think you are asking the wrong question, or maybe asking the right one in the wrong way. The question "Is such-and-such a sin?" is a basic one, and when we are making decisions, it is a very important one, for the first thing we need to do if we want to please Christ and be his follower is to avoid sin. OK. But that is not everything. It is never enough just to avoid sin. Our Christian life is about growth, and specifically growth in love. Just imagine how strange it would seem to you if your Dad were to ask you, "Do you think it would be a sin if I didn't buy Mom some roses for our anniversary?" He would definitely be asking the wrong question, don't you think?

You are pretty sure God is giving you a vocation. You seem to be willing to give him everything. So the question should not be, "Will it be a sin to date?" but, "Will dating be the best way to show God I will put him in the first place, and will it help me keep him there?"

But you have to be clear as to what you mean by dating. I have found some kids refer to normal friendships, groups of friends doing things together, as "dating". However, dating usually means the cultivation of a pretty exclusive friendship between a boy and a girl. Now, in our culture, with our inherent personal weakness and the pressures around us, that may not be the thing to do too soon, even if you don't have a vocation. It usually involves a certain amount of pressure (real or perceived) not to be "strange", and to do "what everybody does"; better not to get drawn into it. Get a good group of friends, whose parents are like your own, and you can have lots of healthy fun and activity without the other pressures.

And keep close to Christ in prayer (rosary, Mass).

God bless,