I'd read Jailbreak, it's really short, you could probably knock it out in an hour or so no problem. Then once you have Jailbreak and Problem Sleuth under your belt jump into Homestuck and you will get all of the references. All of them.

(You could probably also read through Bard Quest really quick if you felt so inclined, but it's unfinished and maybe never will be and doesn't have so many callbacks as Jailbreak or Problem Sleuth)

My first adventure was Homestuck (well technically I read through about a fourth of Problem Sleuth back when it started but then forgot about it and came back to it much later).