Use your Microsoft account through microsoft365.com/setup for everything you want to with Microsoft 365. Create an account or use the account of services such as OneDrive, Skype, Outlook, or Xbox Live. Use the site microsoft365.com/setup to download and install Microsoft 365 setup that will allow you to use multiple apps like Word, Excel, OneNote, PowerPoint, or more.
To see this working, head to your live site.
Sign in to official website from a web browser and start using the apps on the web or access other web services associated with your account such as OneDrive.
How you sign in to an installed Office app depends on your device.
For Office apps installed on a Windows PC:
If you're not already in an Office file or document, open an app such as Word or Excel, and open an existing file, or create a new one.
Select File > Account (or Office Account if you're using Outlook). If you're not already signed in, click Sign In.
In the Sign in window, type the email address and password you use with Office. This might be the personal Microsoft account you associated with Office, or the username and password you use with your work or school account.
Greetings,
Peter