Once you decide you like somebody, there's a natural tendency to place that person in front of your friends and say, "Attention everyone! Look at this person next to me! I like this person! Now you talk to them and like them, too."

Unfortunately, it doesn't always work so smoothly. In your case, you are the newbie placed in a friend group and asked to swim. It can be awkward, intimidating, nerve-racking and annoying. Some people (not you) tend to overcompensate and blast into conversations, overly injecting themselves to overpower the "awk." Others (you), find themselves more buttoned-up and frozen.

Here's a mantra I want you to repeat next time you're with his circle: Its easier to talk to a tree than a forest.

All you need to do is strike up a conversation with one of these "nice people" and let things organically develop from there. Once you are well acquainted with one "tree," it will seamlessly branch out into more interaction.

Tree One: Oh, you went to [insert your College]? So did Fred. Yo, Fred come over here. Did you know [insert your name] went to [insert your College]?
Fred: Oh really, what year?
You: 20xx
Fred: Oh cool, did you know X?

And so on and so on...
 
That's your ticket into this or any overwhelming social sea. Don't treat it like one massive body; approach it as individual fish swimming in the same tank and catch one.