When you click on the OneDrive tile, it will take you to the OneDrive homepage.
Click on My files in the menu on the left side of your screen
This will bring up your files and folders that are saved in OneDrive
You can then hover to the right of a file to bring up the more options icon (...).
Click on it to open, download, rename, delete, etc., the file
If you want to save a file to your OneDrive, click on the + button near the top, left of the screen
and then click Files upload