Hey there! Man City fan here who's been following NYCFC intently since it was first announced, as someone who takes an interest in our youth teams i thought I'd share my opinion of Angelino.
Far as I'm aware Kreis likes his Full Backs to provide width and attack, which is exactly what Angelino excells at. His pace, link up play and footballing intelligence for such a young man will make a fantastic combo with Villa out wide (he and another academy player Barker where a stunning combination this year). He is smart with possession and won't often give the ball away dangerously, along with a decent cross.
A lot of people say his defensive work is sub par but i feel for an attacking Full back its not that bad honestly, he normally has the pace to recover and once he's there he does well enough. His biggest problem is simply this'll be the first time he comes up against men, though he has a great character so don't expect him to shy from the challenge.
Hope that helped
Who would you compare him to? Sounds like Seamus Coleman, but on the left. Coleman sometimes lacks defensive intellect, but makes up for it with his speed. Coleman has been tried as an out and out winger in certain formations, but is usually deployed as a Fullback.