The joke is straightforward. 2 minute cold open of a quick adventure becoming a massive ordeal breaking them, making Rick say they need a vacation which the episode is about.
Your SI is a unique tracking code Google assigned to you. When you share a link to a youtube video, Google puts your SI in the link, even though it doesn't serve a purpose in helping people reach the video. What it does do, when you visit a link with someone else's SI, is tell Google that you followed a link shared by this other person. This lets Google see who you've been talking to on other platforms, and track your relationships and social movement patterns.
Honestly, give it a watch and see if it's for you. Last I saw it was available to stream on Hulu (and uBlock Origin does a good job blocking Hulu's ads)
I found it enjoyable but I don't have a strong need to rewatch it. It's raunchy and absurdist, but does some cool SciFi things I haven't seen elsewhere. But it's way less deep and intellectual than some of its stans seem to think
To be fair, there's a lot of GREAT shows that needed a few episodes to a season to really find themselves.
Rick and Morty took half a season, Supernatural was a slog for over a season until it started leaning into having fun instead of just brooding, the Doctor Who Reboot's production values are distracting for the first season, on and on.
Honestly, the best shows seem to need to go on a bit of a vision quest early on.