I am vary confued why I am Admin and what happened to danny?

so I was clearing out my groups when I noticed I was the admin on danny's group and there are 103 members, I was confused. I talked to danny only once 2 years ago but i guees he made me admin but i never knew about this. But the real question is where is danny, he just disappeared, I even forgot about him un till I discorvered this group.

Anyways, now that I am admin I guees I should make this group active again but I have no idea how to so let's hope this goes well, yes?