There is some etiquette involved. You don't want to be the first person there, just as you should avoid being the 'lingerer' who stays too long or even worse needs to be asked to leave explicitly.
I've heard of "fashionably late", never anything about "early".
IME early bird gets all the good nachos. And you can leave earlier.
Also if you're first, be ready to help set up!
I prefer too ease into these events by starting early and with a small group instead of making an entrance to a full room.
In some cultures appearing a busy person can be important. Showing early to a party could send the message you had nothing to do before. Not that i like or do that, but some people could pay attention to such details.