So if you want to do it in Order first watch the original series NGE.

The ending is pretty out there (VERY meta), and doesn't answer a TON of questions. Thus a lot of fans were pissed so they made 2 movies that "re-wrote" the ending, they are Death and Rebirth and end of eva.

THEN, a bunch of years past till recently and it was decided to distill the ENTIRE series down to 3 movies and change a bunch of stuff. These movies are why the collab came along and it's basically a distilled version of the series without extra fluff and some differences in characters, story flow, etc. these are 1.11 - 2.22 - and 3.33