For what to do this Friday. Need your help

So you see I get done classes at 1:10.

And my little brother from middle school gets off the bus at 2:30

My parents won't be home this Friday so they want me to take care of him.

So that's plan number one is to go straight home after classes.

Plan number two consists of hanging around campus and eating lunch with some friends at 1:30. Then I told one of my friends I'll go to the gym with him at 2:30. And I can just come home after that.

But I really like a cappella and there's an a cappella concert at my school at 8 PM.
And a few of my friends will be in that.

If I went home I would have to stay home because I don't know when my parents will be back.

To make matters worse or not that, but more difficult to decide. Is that I'm handicapped so I will have to rely on getting a ride home from my grandmother when she has time. She can either come at 1 o'clock after my class what they usually come up around 6 o'clock to go to library . And the library is by my dorm next to my college. So I'm conflicted on what to do. And I possibly want to come back to the campus on Sunday to go to the church with some friends. And then small group Bible study with men. I don't know if my friends can help me out but that would be great I haven't asked them yet.

What do I do this Friday?