As for the position of reserve manager, generally speaking, you have to endure several years before you can get promoted. The salary level is actually not high, and it is also quite hard. I don't know if you are a boy or a girl. The working hours of this position are very unstable, and it is common to work until several o'clock in the morning. If you are a girl, I think it may be very hard.
Of course, if you can please your boss, especially the regional director of Yum! (that is, the heads of all the stores in the district), you will be greatly improved.