Wow!
Kol Hakavod to you.
I know that Chai Lifeline has many oppurtunities to do chesed like you describe. I am a volunteer in NJ but I know they have a huge operation in Brooklyn as well. You can become a “big brother”, and do hospital respite.
As well Mesameach in Lakewood is always looking for volunteers to cheer ppl up and visit hospitals, I dont know if they have a base in bklyn also.
As for learning, you can become a Oorah Torah Mate- call them!
Hatzlacha with your quest for chesed!