If finding a file took ten minutes, it'll take ten minutes next time too. Once you've found it, copy the SharePoint link from the browser and save it somewhere obvious — a browser bookmark, a pinned Teams message to yourself, or a OneNote page for processes you don't...
SharePoint search reads the contents of files, not just their names. If you're looking for the expenses policy but can't remember which folder it lives in, try searching expense claim or mileage reimbursement — words you'd expect to see inside it. You'll often find...
A file path starting with C:\ is where that file lives on that person's computer. It won't open for you. Ask them to right-click the file in File Explorer and use Share, or copy the link from their SharePoint browser tab instead. Neither takes more than a few seconds...