I have 2 amounts under box 17 (state income tax). Should I add them up and put a total?

I assume you mean you have an amount in the first row in box 17 and then have an other amount in the row below it. Normally, this happens when you have different state abbreviations in box 15, as the wages are for different states. If this is the case, you should list them separately, the way they are shown on the form.

If they are for the same state, then compare the amounts to the wages in box 1, and if the total equals the box 1 amount, you can add them together. Otherwise, it would be wise to make one entry equal to the wages listed in box 1, assuming you earned all of your income from one state during the year.