If he's outgoing, he'll most likely carry the conversation. All you have to say is hi, how are you. and ask him a random question. From there, the conversation should flow. And if it doesn't, prepare some questions in advance you can ask during silences.
Are you sure you want to be outgoing? Really it sounds like you want to change yourself for this guy, and that's a no-go right away. You will like people you are not meant to be with; you will find all kinds sexy in one way or another for one reason or another that just aren't compatible with you on the whole. Now getting a little more out there sounds healthy, sure, but only if you're really doing it for you.
If you want to catch his attention just be basic and say hello and as about him and all these things and try to get some information on him, ask if he has a Facebook or other social networking tool that will allow you to get a window into who he is and make sure you actually like him. On the same don't jump into his friend circle ( you don't really know what they are like yet, external appearances are rarely the entire picture ), do not do anything extreme to get noticed but instead just generally work up your social standing and popularity ratings, and do not lament not meeting his criteria.
The reason I'm telling you not to do those things is because no matter how you change he may still just not like you.
Just walk up to him, be causal don't let your shyness show, smile at him if possilbe give him a compliment about his clothes guys love it when girls notice little things like that, introduce yourself to him and give him your number.