In most cases you can use Zotero "out of the box" without having to modify any preferences.You will have to make changes to the preferences should you need to:
To access the preferences, open Zotero, select the Actions menu (gear icon), then "Preferences."
Save research to a free Zotero account
Select the "Sync" tab and enter your Zotero user name and password. If you do not have one, select "Create Account" and follow the steps. Once your user name and password have been entered, select "Ok" at the bottom of the Preferences window. Now, all of your research will be saved to an online Zotero account - also any research you previous saved to your Zotero account will be downloaded to the computer you are using.
Save research to your student OneDrive account
Make a new folder on OneDrive called "Zotero" or similar.
In Zotero preferences, go to "Advanced," "Files and Folders," and "Choose" the location of the folder you created. Select "Ok" at the bottom of the window and restart Firefox. You will need to do this on every computer that you use Zotero with OneDrive on.
There are many other preferences that can be modified should you choose. More information is available on Zotero's documentation page.