Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Your Office 365 Home subscription allows you to install on a total of up to 5 PC/Mac class machines. That is total between "your" installs and those shared with family.
It is probably best if you share with them. That way they have their own allocation of 1TB of OneDrive space and 60 minutes Skype time and they access their own email in outlook. Those are totally separate from your allocations of those resources.
Note: when you share, they can install on more than one computer also, up to your combined total of 5 machines! As the owner/"admin" of the license you have control to deallocate those installations.