The male protagonist Ryuki is a rookie Psyncer affiliated with ABIS. He has a more reserved and calm personality. Though he is known for his high academic grades, he has no family as he has lost his parents and younger brother.
Would new players who haven’t played the first game be okay starting with nirvanA Initiative?
No problem at all. The main plot of this game has no relation to the first game at all. Characters that are involved in the inciting incident are mainly new characters. With it being a "new case that needs to be solved," the new characters are on completely equal footing as the previous title's characters.
Main characters from the previous game will appear, but their backstories and relationships are properly explained, so there aren't too many points that you'd need to understand from the previous game.
This game also does not spoil anything from the previous title. It's totally possible to play AI2 and then play AI1.
There's even a special setting for "display information from the previous game for returning players" which you can use to enjoy the story in a deeper way. Isn't that nice of us?