how do I find out my net tax payable, so I know if I can transfer tuition?

[TurboTaxSusan]

Line 42000 of the T1 is Net federal tax. You can see this on your detailed tax summary. 

If you are using TurboTax Online, you can see the detailed tax summary by clicking on the "View detailed summary" at the top of the page. 

In the TurboTax App, click on the menu icon (≡) and select "View detailed summary". 

In TurboTax Desktop EasyStep Mode, click on "View detailed summary" in the top left.