Socially Awkward

Last week, I noticed that I have a slight problem on my hands.

As I was walking to my Geometry class, I passed by a guy I know. Well, I don't know him, but he is friends with all of my other friends. I have seen him at social outings and such, but at this point I still don't feel like I can just approach him and start a casual conversation. So as I was passing by him, I was confronted with a dilemma: Do I or do I not say 'hi'? 

Okay, this is a terribly insignificant problem, which I suppose is a good thing that this is what my daily drama consists of, but it still made me anxious. I feel like he was having similar thoughts about the situation, because we both made brief eye contact, said 'hi' quietly, and I continued on my way briskly. 

Now I am concerned that I am going to have many more uncomfortable confrontations such as this. Anyone have any advice?