Can't upload

I’m totally new to this. I just did the one-click WordPress installation and it ran smoothly and then I tried to copy a theme (unzipped folder, of course) into my wp-content - themes folder via FTP on the dreamhost side and it wouldn’t let me copy the folder over. I got the international “no” symbol and it said I didn’t have permission. Is that a dreamhost problem or a wordpress one?

Any help would be appreciated.