Any apps you need for school can be found in an app called "Self Service." There you will find Notability, Google Drive, Canvas, Explain Everything, etc.
Here is a "how to" for downloading apps from Self-Service:
If you need to download this guide, please see the attached PDF.
YouTube Link: Installing Apps *
*Please know that elementary issued e-Learning iPads do not have YouTube enabled. If you would like to see these videos, please do so on another device.