Sometimes, you have to attend social events, whether you want to or not. The office party (which is a dying event - finally!), a convention (for work or hobby), cocktail parties, Grand Openings or Opening Nights, weddings, funerals, awards ceremonies. They're ubiquitous and no matter how hard you try to be just the person in back getting stuff done, sometimes they force you to the fore or "reward" you by sending you off to that convention.
I know, some of y'all get off on the social stuff and are great and charming and wonderful at them. You already have all the skills you need to breeze through one of these events.
For the rest of us, here are some of my hard-learned lessons in blending in and getting through the obligatory social event.
Dress appropriately. Bathe, wear clean clothes that are the "uniform" of the event - some a good with T-shirt and jeans, others require business semi-formal or formal, others are full on black or white tie events. Find out in advance what type of dress is proper and do your best to blend in. I have a dress I wear to weddings and funerals. At my age, I can get away with dressing the same for both. It's in autumnal colors - russet, olive green, dark brown. The accessories clue in whether it's funereal or celebratory - funereal gets the dark brown shoes, bag, and hat with semi face veil, wedding gets the russet pumps, bag, and fascinator. I tend to wear a turtle neck top and skirt, silly stockings, and sensible flats. For a more formal look, in which case I wear solid colored stockings, and add a jacket over the turtleneck. Luckily, I've never had to attend a full on formal event or a cocktail party. Some of the conventions I attend have an anything goes dress code (from body paint to alien armor), and I sometimes dress steampunk for those because dressing in my turtleneck out fit stands out, but wearing a bustle and a visible corset doesn't.
Arrive at your social event slightly late. Again, you don't want to be the first one to arrive and you don't want to be the one who is always late in order to "make an entrance." Arrive a few minutes late and blend in with the crowd. I was always one of those "too early" people until I learned to wait in the car until I'd seen 3 or 4 other people go in ahead of me. For meetings, panels, demonstrations, etc, be a bit early or on time, but for social events, try to enter with most of the others.
Make small talk. Or at least pretend to. If you can get the other person to talking, you're golden. Then, all you have to do is interject the occasional "is that so?", "interesting", "uh huh", "I hear you" interspersed with a few nods or shakes of your head. This is a real lifesaver for me because half the time I can't hear what they're saying anyway.
Don't give out too much information. You may have to be social but that doesn't mean you have to bare all. Make your work sound as uninteresting as possible, don't talk personal finances (this is a social event, not your CPA's office), avoid politics, avoid religion. Of course, if it's a political caucus or fund-raiser dinner, then politics is probably obligatory - listening is still better than talking. And if it's a religious retreat or something, then you'll probably at least mention religion. But on the whole, religion, politics, finances, and work are off the table as topics. Encourage the other person to talk. Food is an excellent topic. Everyone eats, and likely there's food being served so you can talk about that. Fashion is another decent topic - everyone wears something. Gardening and flowers are other safe topics. The weather is a decent topic if it's been a news headliner or you're new to the area.
Mind your manners. Don't be either overly formal or overly casual. Do take a hint from how the majority of attendees are behaving. If a meal is being served, and you aren't sure about the protocols of when to start, pay attention to those at the table with you or at surrounding tables. If it's a buffet, only take a small amount at a time and return frequently - this gives you both something to talk about and a reason to wander away quickly ("I have to return my plate"). Turn your cell phone to vibrate and if you get a call, retire somewhere private to return it - or better still, return the call after the event. Most only last a couple of hours and most calls can wait. Truly, they can.
Mind your presence. Everyone has a presence. The way you walk, the way you gesture, your facial expression when you aren't paying attention, the amount of eye contact you make, the way you wear your clothes, that sort of thing. You will be treated differently if your presence screams "thug" or "jittery mouse". Consider that. Me, I tend to be "the girl with the cute little dog" (girl, even though I'm old enough to be granny to most of the attendees, because I have a cute little froo-froo service dog), so I am always a little more memorable than I'd like to be and get more attention than either of us wants, but we've learned to deal with it.
A bit of confidence (exhibited by a sweet smile or at least by relaxed features), charm (exhibited by looking directly at the person to whom you are talking), and attitude (exhibited by your nods and the way you move on to the next person) will go a long way towards making you seem...very average. Unless you want to be the most confident guy, the most charming guy, or the guy with the most attitude, your best bet is to be average. You'll have the most fun, get through with the least hassles, and have the least panic attacks.
Hold your alcohol. One drink is fine, eight drinks is stupid. You don't want pictures of you soused and silly showing up in places that could cause you harm later on - in the workplace, most likely, seeing as your bosses probably feel they own you even in your leisure time. If you don't want you boss, your children, your mother, seeing it, don't do it.
Avoid the cameras. Again, this is because some people do their best to try to get you in a comprising position - they think it's funny. I don't have to worry about it too much - everyone wants to photograph Itzl, and the most photographed part of me is my turtleneck clad bosom. Maybe a hand gets seen, too. Unless you are deliberately posing for a picture, try to avoid the candid shots. At some events - weddings, anniversaries - pictures are obligatory, Suck it up, pose and smile when you need to, and avoid the candid shots if you can.
Listen and pay attention. Social gatherings are a great place to learn new things and discover the latest on-dits. You can glean a lot of useful information just listening and paying attention. Co-workers will tell you the latest office gossip, and you might learn about a re-organization. In purely social circles, you might learn about new family members, or who just lost a job and might need a secret benefactor. You might learn about new city projects coming up or a struggling charity.
Leave. Obviously, if you go to something, you also have to leave it at some point. Unless it's a true emergency, don't leave shortly after you arrive. Mingle, eat a bit, listen a lot, and when you notice others beginning to leave, find the host/ess and take your leave. Don't sneak out. The host/ess put a lot of effort into creating this event, the least you can do is find them, tell them they did a marvelous job and you appreciate their efforts, it looks like every had a great time and you're pleased they included you. Then leave. You don't have to take your leave of each and every person there, but you do have to do so with the host/ess. It's common courtesy and part of the minding your manners thing.
If you do these things, you can get through most social events easily, be welcomed at future ones, and may, someday, find they aren't the ordeal you first thought them. You might even come to enjoy them.