The interview was very easy. I would dress somewhat professional for first impressions but it's a very casual interview and if you're doing it in person, they just take you to the back room. My suggestion is don't apply online because you won't be interviewed by the store manager. You'll be interviewed by HR and I think it's better to interview and get to know who your potential manager is. As for the interview itself, they mostly ask about personal experiences so be prepared to think back to situations you've encountered.