Thank you so much for your help but I actually solved it! I'll post here what happened just in case someone else finds themselves in this situation.
There was a conflict between web.config files. I had one in the root folder that I copied over and still had the same file in my subdirectory. I simply had to delete that file in my subdirectory and it worked.
However, I also had a separate blog subdirectory. When I deleted that web.config file, I could see the site and it had the theme installed, but it couldn't find individual posts. Turns out this was a problem with permalinks. So I put the web.config file back in that particular subdirectory but had to change the rule name so it did not conflict with the root web.config file. This post was very helpful in understanding what needed to be done.