Applied at Culver's for Team Member

I recently interviewed for a Team Member position at Culver's and have another interview coming up on Monday. However, I also interviewed for a part-time Retail Stocking Associate position at Burlington, and the interviewer encouraged me to follow up if I hadn't heard back by Monday. I'm feeling a bit overwhelmed because I don't know what to do if both companies offer me a job on the same day or if Burlington offers me a position before my interview with Culver's. If Burlington calls first, should I accept their offer and cancel my Culver's interview, or should I still go to the interview just in case? I'm worried about how long job offers stay open and fear that if I don't accept Burlington's offer quickly, they might give it to someone else. I'm also concerned about the pay. Burlington's starting pay is $13.50 an hour, while Culver's has a range of $11 to $16 an hour. Since this would be my first job and I don't have previous experience, I'm unsure where I might fall within that pay range. I hope to earn at least $15 an hour, but I'm worried Culver's might only offer me the minimum of $11. Is it appropriate to ask for a higher starting wage for my first job? I'm really looking for advice from anyone with experience at either company or in hiring in general.