So quick background.
-Always had trouble with making/keeping friends.
-I am an extremely awkward person on a good day
-I'm 24 my husband is 33
-got married and had kids 4 years ago and haven't had a single friend since.
-seriously I haven't spoken to anyone that I'm not related to in 4 years.
-not exactly by choice, my social/general anxiety has slowly been getting worse and worse the longer I'm away from people.

Alright so now what I need help with.
My husband got invited out with a group of his friends from his old Mechanic shop, and they said to bring me along too. (I met my husband when I got a job as a car detailer at this shop, so they all know me fairly well.) 
So all I've been able to get out of my husband is that they'll "probably" bring their wives with them too. 
So I'm now going into a situation where all the guys there are people I kind-of know, and they're all in their 30's. Let alone meeting all their wives for the first time and trying to figure out things I might have in common with them to talk about.
I stopped being "socially active" when I was 20 so I have no idea how to fit in with them. I have nothing in common with anyone. I'm a weird, nerdy artist/gamer who spends everyday home alone with her kids and pets. 
Please help. How do I talk to people? Without being an embarrassment to myself or my husband?