Would like to try dating, but no idea where to begin/

Some background: I am 20 years old, a marathon runner, a civil engineering student and all around a fairly busy and focused guy.

Normally I sort of just through the thought of dating and relationships to the side. However recently something changed that and now I would like to try to give dating a shot. I had one short thing for a month the summer after Junior year of high school but nothing besides that. Since then I have had random run ins where girls, but that led no where. I also have never made a move on a girl, and seem to never realize if a girl is hitting on my till the next day.

However recently I am seeing that there are a lot more girls with whom I would be interested in dating. Can anyone give some advice for how one would introduce themselves into the world of dating?