Firstly, go to your browser either Chrome or Edge.
If you cannot see Edge or Chrome, you can simply type it in, in the search bar at the bottom.
Secondly once in Chrome or Edge go up to the search bar at the top of the page and type in portal.office.com or you can type office.com
Then press Enter and you should be taken to this page.
You may also see this page if you have typed in Office.com
You then want to click Sign in or just input your school email address and then press Enter, which will take you to the password section.
This is where you want to input your password you use on the school computers.
Once logging in you will be faced with this page.
Down the left-hand side, you should see all your Microsoft applications such as Word, Excel, PowerPoint, Outlook, OneDrive etc.
You can create documents on Office 365 and they will automatically save to your OneDrive.