Need help with the Auction Theme / orders mainly

First of all, I need to figure out where I can make the “Pay Now” button open in a new window. We are only using Authorize.net as the payment method, and it opens an Authorize.net payment form in the same tab, taking them off my auction site (https://bgcbcauctions.com).

Then after payment is made it stays on the Authorize.net thank you for your order receipt screen (screenshot attached), and does not redirect back to the website.

Then, in Order Manager, it does not show an Order in there after the payment was successful. (screenshot attached)

No emails are sent to the seller or the buyer that an order was processed.

When the buyer returns to the screen that has the “pay now” button, it is still there, even though he already paid. (screenshot attached)

This is very urgent, as a major newspaper is going to be posting an article in the paper sending people to this website for this auction in the next couple of days and I have to get this site finished. It only has 12 items for sale, but I can’t get this thing working right. Please help me quickly. I can provide backend access if needed.