Do stores hire customers?

Backstory - I am a college student majoring in IT Engineering with a part time job. I just got laid off my job, and I need to find a job asap. There is a smoke shop right around the corner from where I live that I frequently go to for the past 2 years. The owners are 2 brothers. They are very cool people. They know I'm in school, and they even gave me some free weed when I finished the 2024 fall semester off with a 4.0 GPA.

My question is this - I have an idea of going down there and applying for a job. They always have help wanted signs on the counters. They are always switching between customer service representatives (they've gone through 7 different one's since I've started going there 2 years ago).

Do stores have any issues with hiring their customers to work for them? I'm not sure if there is some insider secret code or rule that you don't hire your customers. Or am I just being too optimistic?

I'm going to wear my Sunday best suit. My resume printed out. I've gotten a haircut, trimmed and I look professional. I want to make a good first impression if I do this. Just like any other job.

(I don't have any sales or retail experience at all)