how do I overcome my shyness when im with my boyfriend and his fri

I am so terribly shy and the guy who I have known for about 4 years now (and dated for 2 months 2 years ago) asked me out this morning and I said yea, so we’re dating now and its all very exciting and everything… but a little bit before that he also asked me if I wanted to come over this weekend and hang out with him and his friends because his guyfriends are bringing their girlfriends too, and I said yes to that as well. he is important to me and I want his friends to approve of me and all that good stuff ya know… I mean, I want to fit into his life. earlier I was excited about his inviting me because the friends that he generally has me with him to hang out with are people that I know or that I at least was acquainted with from high school (I graduated 2 years ago). but I dont know who he’s inviting over this weekend. im assuming I know at least one of the guys he’s invited, as the two are close friends and I’ve met most if not all of his CLOSE friends. but oh man I am NERVOUS! I dont want to be a wallflower, the awkward shy girl, ya know? but I dont know if I am going to be able to interact with these guys, the people hes having over are typically interested in hunting, mudding, trucks, paintball, and videogames and I know NOTHING about ANY of those subjects. and I think they know eachother so how am I supposed to talk to people who are too busy talking to eachother to notice me. thats what im afraid of. what if theyre all talkin to each other havin a good time an just barely notice the quiet girl sitting there staring at everyone. ahhh! I have real anxiety in social situations I really do its awful please help me out here. how do I be more social? what on the earth do I talk to these people about??