The opening crawl will tell us that the story of how Luke Skywalker’s battle with Kylo Ren has inspired many throughout the galaxy.
Star Wars: The Last Jedi opened meer moments after The Force Awakens had ended, but that was an unusual move for the franchise.
The rebels have been on the run, the Clone Wars have raged across the galaxy, etc. I would expect that Episode IX will go back to this practice and begin several years after The Last Jedi.
However, nothing has united so many people as when they came together to pay their respects to a lost friend.