coach coach coach!! your shifts and sm will be watching you, and likely already are if they know your goals. coach your partners at every possible chance. if they’re doing something wrong or ask a question be the first one to offer support.
honestly i would ask your store! the people you work with the most, especially your shifts and sm, will know what you need to work on. sit down with them and explain you want to advance, and ask what they think you can work on to be better. my manager laid out for me very clearly where she wanted to see improvements if i was serious. just got the job today!!!
good luck <3

I recently went through the process and got the promotion ! Most of the questions they ask revolve around scenarios. I would say the biggest thing they look for is coaching and showing you have what it takes to be a leader. Good luck! :)

Are you already a barista ?

Don’t. Go back to college.