What do people do at cocktail parties?

At a social hour at my coworking space today, there was a bar with food and drinks set out but nobody was standing around available to approach. I don’t understand what to do if you don’t have anyone to talk to. I feel like I put pressure to find someone to talk to because what are you supposed to do if you’re out alone? Do you stand there with a drink in your hand waiting for someone to approach you? Where do you put your eyes?