Below is a demonstrative video. The steps are also written out below.
1.) Start up and sign into your desktop/laptop so that you are at the home windows page.
2.) Look at the bottom right of your screen in the tray there should be an upwards pointing arrow. Left click on the arrow.
3.) Press the little grey/striked-through cloud. This is the OneDrive Icon.
4.) The following screen will either say welcome to OneDrive, in which case you will press the button on the bottom right which reads "Get Started". Or it will say Sign in, in which case you will enter your school email and password. Alternatively, if you don't have an account press the blue "Create one!" text. Follow the on screen instructions to create an account.