Hello. My name is Michael. I can help you with your question.
Even if something has happened to your application, your documents should still be where they were - they are actually totally separate. So don't worry about the documents getting lost.
You are looking for a folder named "Microsoft Office 2011".
It belongs in your Applications folder, but you can't search that folder with spotlight/finder, you need to scan your Applications folder manually, Spotlight doesn't work there.
If the folder is not there, next check your Trash folder. If you find it there, right-click and choose "Put back".
Otherwise, assume that you may have "moved" it mistakenly. This can happen with an errant click and drag... Check the other folders near Applications first. If it was dragged, that's most likely where it would have been dragged. Then check the folders close to where "Microsoft" would appear in your Applications folder.
Otherwise, you will need to re-install and re-update it. Once you do, you will be able to open your word documents again without a problem. Please let me know if this answers your question or if you need additional help.