Here are some ideas for the main season plot-lines, including what I think would be a fun and random crossover.
Synopsis: DJ, Steph, Michelle, Nicky, and Alex are going through high school/college.(DJ and Steph can be attending the same college (insert generic bay area college name here), while the other three go to the same high school, or whatever combinations will make sense based on the age of their characters (DJ could be pursuing her masters degree, or something like that). Let's throw in a few Kimmy Gibbler and Steve cameos too, for old times sake.
DJ and/or Steph, in their attempts to move off-campus, wind up living next to the fraternity house of Delta Psi Beta. Hilarity ensues as the gang encounter the leaders of the frat, Teddy and Pete (Zac Efron and Dave Franco), with Danny, Joey, Jesse, and Becky swooping in to try and figure things out immediately. Cameos throughout the season can include Steph Curry/Klay Thompson, Colin Kaepernick/Patrick Willis, Lil B, and Buster Posey/Madison Bumgarner.
By forging new friendships and overcoming new forms of adversity, the season ultimately ends with the entire Tanner squad performing at a Beach Boys reunion concert, with all the season cameos and frat boys singing along and watching in amazement on the side, followed by a huge party thrown at the frat house, culminating in a dance battle between Danny, Jesse, Teddy, Joey, Lil B and Steph Curry. The party comes crashing down to a halt, as the frat boys accidentally start a house fire. No one ends up dead, but the house is completely destroyed. The boys find a new place to move to, while the Full House Gang takes another trip to Disney World.