On your home screen, look for the App Store application. Tap on it to open.
Similarly, if you swipe down while on your home screen, your spotlight search will open up. Type in App Store to find it.
Once inside the App Store, in the search bar at the top. Type in OneDrive. Either press Enter or tap on the top suggested search(Normally is OneDrive).
Generally, OneDrive will be the first suggested app. Click Get. You will be asked to enter your Apple ID & password. Then the application will begin download.
Once the download is complete, you can also open the application from the App Store. Press Open.
Once the OneDrive app has opened, you will have to enter your Microsoft email account and password to proceed.
Once signed in, OneDrive will take you to the Home section. Here is a rundown of the app layout.
Home:
Files:
This shows all files and folders within your OneDrive (will be similar to the one in your computer).
To add a file/folder etc, press the “+” at the top right. There will be a drop down showing all the options to add to your OneDrive.
Camera:
Shared:
Libraries: