In a *nix file system, ./ and ../ are "listed" in a file directory as navigation points. These indicate the current folder and the folder directly above it, respectively.
Use ls -la to print out a list of all files, hidden or not, in the folder. If the two navigation points you mentioned come up, and nothing else, the folder is empty. Some files and folders that start with a . may be hidden and will show up with the ls -la command.
You can use rm -rf path/to/folder/ to clear any files from that folder. Use with care, it is irreversible.
