New MBTA Heavy Rail Operator

Hi, I'm starting training soon to be a heavy rail operator, in January coming up. I was wondering what line should I pick. I’ve been hearing blue line is the best line, and always liked the blue. I also live in mattapan. I have a car but have car trouble right now so I’m taking public transportation and don’t mind getting up early. I’m just concerned about getting out late and having trouble getting home.

Any advice ?