My first time as well, so not sure how helpful I'll be, buuut I'll second how great people on Discord have been. Great place to just hang out and play games with Geeklies if you're into video games. The ones that I've seen mostly played have been PUBG, Armello, Tabletop Simulator, Overwatch, Heroes of the Storm, Minecraft, and Destiny 2 (though it's been a while since that was popular). I know WoW also has a strong following. A couple of us also play League, but that doesn't seem as played on the Discord.
But yeah, I think one way to make it less intimidating would be if you make some friends on the Discord who are also going to GeeklyCon so you might be able to meet up with them in person to have someone you're more familiar with rather than being overwhelmed by nothing but total strangers.
If you're not as into video games, it may not work out that way as well, so main thing I'd say is that from what I've heard, GeeklyCon is full of socially awkward people who are actually super nice.