Glee: A New Beginning overlaps seasons 5b and 6. Only the episodes New New York and Opening Night are considered cannon and everything else is AU.
It begins in September, about a month after Artie moves to New York around August 1. It takes place almost exclusively in Lima, but there will be references to the New York people from time to time, and an occasional trip there. Artie is the only New Yorker whom I expect to appear in Lima to any significant degree, but not in every episode.
In New York, Artie is having issues settling in because only one of his loves (film school) is there with him. The other (Kitty) is still in Lima. Unlike the show Artie and Kitty aren’t formally broken up. They each have permission to see others if they so desire and plan to reconnect again in two years unless things change for one or both of them. This ends up being more confusing and frustrating for both of them. Artie DOES date, but does not hook up, in an attempt to distract himself but it doesn’t work. After a few months they realize that this doesn’t work for them and decide to just do a long distance relationship.
In Lima, Sue has eliminated glee club, but no one has transferred out. Mr. Schue decides to invest the energies he had been investing in Glee Club into Drama Club. All of the former glee members and some other familiar faces join that. Among the familiar faces are Betty Pillsbury (Emma’s wheelchair bound niece), Jordan Stern (Neck Brace Cheerio), and Marissa (the image of Ryder’s Catfish). We will also be introducing freshmen twin cheerios Mason and Madison McCarthy.
Of course this is really just to bide their time until they manage to get Glee Club back, which does happen by the end of the year.
In the second part (season 6 time-frame), Glee is back. They have ONE YEAR to prove themselves or be gone again. The remainder of the season six newbies will be introduced here and we will do a virtual season of Glee with lessons and competitions. As in season 6 of the show Kitty is captain, but Marley and the others are still around and play prominent roles themselves. It’s a Wildebrams story so of course Artie will make regular appearances (though not always in person), but he is in film school in New York.
Unlike the show, no one gives up on their dreams for no apparent reason. Rahel is still doing Funny Girl on Broadway, and Blaine and Kurt are in NYADA. Quinn and Tina are at their respective colleges, Puck, the Air Force. Mercedes and Santana are off perusing their dreams along with Brittany. Will never left to go to Carmel High.