Employers can put just about anything in box 14; it's a catch-all for items that don't have their own dedicated box on the W-2. Unless you work for a railroad most entries are just informational.
In TurboTax, enter the description from your W-2's box 14 on the first field in the row. Enter the dollar amount and select the correct tax category that goes with that description.
If none of the categories apply, scroll to the bottom of the list and choose Other (not classified). Don’t worry. We'll figure out if it impacts your return or not. If we need more information, we'll ask you.
If box 14 is blank, just skip over it. Don't enter a 0 for any blank boxes.