How do I talk to a guy I like?

I got to my dads house in the weekends and theres this guy that I see all the time at the pool and at the roller rink and I'm a very shy person and I want to no how to start a conversation with him. But not come off as kreepy. He seems out going, my dad stayed at the roller rink one night and he just went up to my dad talking to him about the hawkeyes. I wish he would come up to me and talk to me like that.