Should I focus on just one character as I'm starting out?

Hello! I've been wanting to get into fighting games for a long time now and I decided to start with Guilty Gear Strive. I have only about twelve hours, almost all of it in the missions or training. I heard that you should try to get good with one character so I've been trying to decide a character to start out with but I just really can't decide. I really like Bridget, I-no, Giovanna, Ramlethal, Jack-o, and Millia. I've been going mostly with Bridget because she's the reason I started and has the easiest time learning but I'm really not sure. Any advice on who or how to pick? Or do I even have to focus on one character?