A family of Microsoft word processing software products for creating web, email, and print documents.
First make sure that you haven't just lost the shortcuts for yor Office programs. If you click the Start button in Windows 10 and then start typing winword, you should see Word in the list of search results. Right-click it and choose to pin it to the Start menu and/or the taskbar. Do the same with Excel and PowerPoint.
If that doesn't work, note that resetting the computer might mean that it was restored to state it was in before you first installed Office. If that is indeed what has happened, you will have to reinstall Office using your product key. You can download a backup from https://products.office.com/en-us/download-back-up-restore-microsoft-office-products.