What should I do if the job I was working for sold out and I don't have a way to contact the old business for my w-2

If you cannot get a W-2 from your old employer, then you will simply need to include form 4852 with your return.  You can use your last pay stub to figure out how much you earned and had withheld. You can do this in TurboTax by entering your information as if you had a W-2 then selecting "Didn't get a W-2 (manually calculate my earnings)" in TurboTax on the screen after the W-2 entry.  TurboTax will then walk you through the steps of filing the form.  Form 4852 cannot be e-filed, so you will need to paper mail your return. 

Whoever bought the business will probably send out W-2s for the old business. They have until January 31 to mail them, and it would take a few days for the mail to get to you. So wait a couple of weeks to see if you get a W-2 before you assume that you're not getting one.

You could also contact the purchaser of the business and ask them what they are doing about W-2s for employees of the old business.