With SIR this year, starts are not the typical mass starts. You leave anytime from start time to an hour later, and write down your own start time. At least that's how they ran the 300k. It was super weird to sitting at Starbucks at 6:05AM, chilling out with our coffee and sandwiches, in no particular rush to wolf our food down and start. I think we departed at a leisurely 6:20 on a planned 6:00am start. That does lead to less socialization and more riding alone or in small groups. Controls are all info controls, so how much you go into stores/restaurants is wholly dependent on your desires/needs. On the 300, they had a staffed control at the halfway with sandwiches, snacks, and water. They had cold pizza and beverages at the finish.
I rode the 300k with a buddy. We saw other randos at stops etc, interacted a bit outside a Safeway, but otherwise it was the two of us on a solo ride.
There will be a summer SR series, as well as a June 100k populaire.
I think it's fine to start rando this year, but it's atypical in that there will be limited social interaction. I suppose you're a bit more self sufficient than normal, as well. Sign up for the June pop, see what it's like.