To select a folder, click on the folder name or icon. The folder will appear with yellow background. To deselect the folder click the selected folder again
To move a file or folder click on the the name of the file or folder and drag it into the folder you want it to be in. You can only move items that you have write permission to into folders you have write premission to.
To update a file or folder use the icon that appears when you hover over a file or folder. The icon will only appear for items you have write permission to