If you cannot find a file or folder, you can search for it:
In File Explorer, press F3 or Control + E to go to the Search box. Start typing in the name of the file or folder and the list will automatically update in the File Explorer window. Tab twice to go to the list of search results, arrow down to find your file/folder and press Enter to open it. This search will just concentrate on the current folder.
You can also search for files based on type, size, when last modified.
Follow this link to find out how to do more advanced file searches.