Can I add a w2 to my income that is not related to my business. How do I do that?

Yes.  Are you filling out a personal 1040 return with Schedule C for your Business?  What Turbo Tax version do you have?

To Add a W2 enter it under

Federal Taxes or Personal (Home & Business)

Wages & Income  

Then Wages and Salaries- Click the Start or Update button

Then if you are married you should have 2 buttons...Add w-2 for (taxpayer name) and Add w-2 for (spouse name). Click on the correct button to add a W-2.

Yes, you have to enter all of your income on your tax return.   How do I manually enter my W-2?