The justice league and Batman and superman movies, ok good stuff, i will check them out.....oh and you talk about one of them having a directors cut, is this the same type of thing that happened to the Reeves Superman II that got the original directors cut, which in my view made the movie a more true sequal to the first, and dumped a lot of the pointless humor making it a bit darker, which i liked a lot.
Yeah i know, i am about 30 years behind in this stuff, i still have more dvds than Blu rays. Lol
If you want a straight narrative for the universe the Flash occupied (including stories / events before his first appearance in BvS, and films whether he appeared in them or not), I would start with:
Man of Steel
Batman v Superman: Dawn of Justice - Ultimate Edition (MoS & BvS/UE launched rather strong, iconic versions of DC characters who felt like more than just the name and costume)
Wonder Woman
Suicide Squad
Zack Snyder's Justice League (The Justice League film one would want, with enough care relevant to the films which preceded it to justify heroes getting together for reasons other than just getting together. Excellent film, and sets the concept straight after the misguided, creatively challenged disaster that was the theatrical version helmed by Whedon after Snyder's departure due to the tragedy of his daughter's suicide).
Aquaman
The Flash
...and not a necessity, but Black Adam is worth one screening, as you get a strong representation for the Justice Society and other gems.
His appearance in the so-named Arrowverse is brief and forgettable.
I hope you enjoy the journey.