"Grinding"? Well, how much any given person grinds at a club depends on what they've gone for. It's not compulsory, you know. I've been to a fair variety of clubs in my time but not seen much grinding going on at all. In fact, now I think about it, I don't think I've actually seen any. Even though the vast majority of the time I've gone with my other half, we might only grind rarely - it's virtually unheard of for us two. So I really wouldn't worry about that as an issue.
The reason we both used to go (still go, but rarely) to clubs is to be in an atmosphere you don't really get anywhere else: one in which people are ubeat and happy, enjoying themselves, a place where people make short, temporary friendships with strangers. It reminds me of the goodness of human nature, and there are many who do the same. Finding a sexual partner may be on some peoples' list, but not everybody's, and it depends on what kind of club you go to. If you go to a meat market with cheap entry that doesn't tell you what the DJ's name is, you can guess it's more of a find-a-bedfellow night.
I've been mostly to the kind of night where they actually tell you who the DJ(s) is/are going to be. The ticket is more expensive for such a place and you might have to book tickets ahead of time, but those places are worth it. Different DJs have different styles, just like different singers or bands, which is why this is a good indicator of the quality of a night. If someone's paid enough money for a reasonable-quality Tshirt to get into a club, you can guess they're there to listen to the music and socialise non-sexually with like-minded people.
As for dancing... you'll get the idea when you go there. I've only very rarely indeed seen anyone do a proper, structured dance in a club. It's just not done. Mostly dancing in a club is just a mess of limbs to be honest.
As for areas to socialise in, that depends on the club. To me, a good club has a dancefloor, the bar is separate enough from the main dancing area so that you can actually queue for a drink without being constantly elbowed by a dancer, and a seating area also nicely-separate from the dancing area and ideally in its own room or behind a corner/screen so that you're shielded from the worst of the sound, therefore facilitating conversation. The seating area should have enough seats that at least a couple of dozen people can lounge there at any given time.
Certainly having a drink or two will make all of this easier, as it can be an alien place to go when you're unfamiliar with clubbing. No need to go overboard with the drink either: I don't, if I'm honest.
If you have any further questions, just ask - I'm perfectly happy to expand on anything.
