ACK!!! I really messed this up

So I'm blogging last night and I decided to quickly change my template into something a little more fun. Yeah, that didn't go so well. I spent over an hour and a half and now I can only download the starting templates. When I download (or is it upload?) from any other website I get the starting template center writing space in front of the downloaded template. I finally gave up at 1:30am. So, if any of you computer-literate geniuses out there know what I did, and how to fix it, I'm at your beck and call. I really want the center writing area to be wider; there is so much wasted space on the ones I have used.