Yeah and tidy
Meet and tidy
Just be smart enough to look like one and don't go excessively formal but tidy up yourself.
If with the store manager, go casual
Casual enough for an interview in the adjacent food court.
Suits are not necessary. Just be you. As long your hair doesn't look like a mop, shoes haven't come out the trash or attire doesn't have bad words or slogans on it, you'll be fine. JB Hi-Fi is a very relaxed, casual environment.
Right clean shirt or suits and right altitude and make sure you smell good also brush your hair be on time