I still do the party-host thing and yall can, too! (Thanks Mad Men for teaching me a lot of outmoded social scripts... no really tho)
Remember things about your friends! Ask people about their weekends, hobbies, holidays, studies, and jobs! Listen for the concerns people have and what they are working on! Draw connections between one person and another to get the ball rolling. "Oh, Maura, you just got your first cat! You should talk to Felix, he used to work at a rescue. Felix, please tell Maura all the new-cat-guardian pointers."
"Bill, Sheila, Xan, this is my friend Kale. Kale is really into Star Trek, Bill you and them should talk about it!"
Orrr whatever! After you make the introduction and draw the connection you just float on into the next interaction with someone else at the function. Just listen, care about your friends, get our of your own head, and think of how you can bring other people together and you will feel 100% less awkward.