If you're working on a library computer, there's another easy option for taking your Zotero library with you.
On your computer, click the Zotero gear menu, choose Export Library, and save the file to your USB drive. On the library's computer, click the gear menu, choose Import, and find your Zotero file to import it.
When you're done, make sure to export any changes and import the new file onto your computer. The library's computers will erase your data when you log off.