Wait?!?! is nightwing robin cause. . . im totally CoNFuseD

Yeah, Nightwing is Robin. tu see, in the comics, Dick Grayson, the first Robin, after joining the Teen Titans and facing The Judas Contract, in an attempt to distance himself from Batman, dawned his own new identity; Nightwing. Since the series jumped ahead 5 years, similar to when the comics skipped one año after Infinite Crisis, a grown-up Robin emerges as Nightwing (following the flow of the comics). Hope that helps

the robin from the 2012 team was Dick Grayson. In the 2016 team Dick Grayson is now Nightwing.

Yes

Yes.
In the segundo season there was a new robin and the old one robin from season 1 became nightwing

Dick Grayson is Robin in YJ:I. There is this whole complicated thing about how Dick becomes Nightwing and is replaced por Jason Todd, who dies (in the sacred hall of dead heroes thing in episode 9) and is then replaced again por Tim Drake, the Robin in the new show. There are actually 5-6 Robins in total (not sure). I don't know if they will have all of them though... that's all I know. :)