You just need to determine what you're comfortable sharing. The interview is about you having the opportunity to see if this is a company you want to work for, and for the company to see if you would do well. Remember- you can always change your mind if you want a new job.

Remember that if they ask you about getting off work- it's more of a conversation filler than an actual interview question. They'll most likely ask as they lead you to the interview room or greet you when you arrive.

You don't have to provide a direct answer- you can just say, "It was no problem at all- I'm just happy to have the opportunity to interview with you." That's a truthful response and it doesn't put you in a situation where you're lying.

Good luck!