Thought I had lost the blog for a minute

I tried to use a free template I found, and when realised I didn't know how to get my blog data showing up through it, I went to paste it back and thought I had actually not saved my old template, (I'm stoned) but thank Christ I did. You couldn't see any posts or anything, at one point I messed it up so bad there was just a white screen under the nav bar where my blog should have been!
I'll ask some of my friends who've used these templates how they did it, then try again, tentatively, when I get over the trauma of nearly losing a years worth of blogging because I tried to play with HTML while I was stoned.