First off, welcome to Listia! Now to attempt to help you out, getting started with auctions, and dealing with the people on Listia. You need to get "verified" through Listia. It will help people to feel more confident bidding on your auctions, and you'll get more credits for the items you list. Next, everyone has a life outside of Listia, so people understand when you can't always get back to them the same day when they leave a comment, or ask a question. That said, you do need to respond as soon as you possibly can, so people won't worry about whether or not you will follow through with your auction. This is especially important when your account is new. As time goes on, and your feedback rating stays positive, people will cut you more slack, because they'll see that you have followed through on past auctions.
Just trying to give you a little help, so you get going on the right foot. Good luck with your auction, and welcome to Listia again!
Oh, one more thing. You have questions on here from a couple days ago, that you haven't responded to. Every time you check in on the site, you should address any questions/comments. The reason is, people can see when the last time was, that you were on Listia. So everyone knows that you were on here 9/7, but haven't answered the questions from 9/5 & 9/6. That makes people think you aren't legitimate.