How do I find an old w2 on this website

As stated on the back of the W-2 -
Keep Copy C of Form W-2 for at least 3 years after the due date for filing your income tax return. However, to help protect your social security benefits, keep Copy C until you begin receiving social security benefits, just in case there is a question about your work record and/or earnings in a particular year.

TurboTax does not have a copy of the W-2 or Form 1099.

It would have a Form W-2 Wage and Tax Statement that included the tax data from the forms that were entered.
The forms would be included in the PDF of the tax return in the tax year the return was completed.

Copies of a Form 1099 would have to obtained from the issuer of the form.

To access your current or prior year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/

Scroll down to the section Your tax returns & documents. Click on the Year and Click on Download/print return (PDF)

If you cannot obtain the W-2 from your employer, then for a fee you can get a complete copy of a W-2 from the Social Security Administration - https://faq.ssa.gov/en-us/Topic/article/KA-02501

You can get a free Wage and Income transcript from the IRS - https://www.irs.gov/individuals/get-transcript

For a fee of $30 you can get a complete federal tax return to include copies of W-2's, if you mailed the tax return and included a paper W-2, from the IRS by completing Form 4506 - http://www.irs.gov/pub/irs-pdf/f4506.pdf

See this IRS Tax Topic - http://www.irs.gov/taxtopics/tc159.html