Be careful with the assistant manager positions. I don't know if you've been offered salary or not, but I took a job like that in college and wound up working tons of overtime (which they no longer had to pay me for) and basically felt as if I lost the ability to set limits on my job. You may have been offered an hourly position, which would be better.
It would be hourly. The only way i could get salary is if i was the store owner. Which I will pass. I just know they want me on the call at any moment. And my boss is already this way with me now.