Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
1
Click your Start Button, then just type word.
In the resulting list, do you see the Word app and if so are you able to open Word from there.
If not, please provide a screenshot of the error indicated.
2
Log into any Microsoft account you may have on this link, do you find your subscription to Microsoft 365 listed and if so, is the expiry date on the subscription listed correctly.