I'm trying to change my banking information. the help menu said to click "start" next to step 2 in the "file" menu. there is no "start" button.

Try closing TurboTax, clear your Cache and Cookies if you are using TurboTax Online, and reopen TurboTax.  You can also try a different browser.

 

Also, make sure you have ran all updates. 

 

If using TurboTax Online: Clear your cache and cookies. See this FAQ, for your particular browser.

If using TurboTax Desktop: Please see this FAQ.