In the Online version of Turbotax, can I view forms such as Schedule 3 (Capitol Gains), or the information used for that form that was downloaded from CRA?

You can see a detailed summary of your return in the online edition of TurboTax by following the instructions on this TurboTax FAQ: How can I see a detailed summary of my return in TurboTax Online?

You can also see the actual CRA forms that make up your return by saving/printing your return. This TurboTax FAQ tells you how to save/print a copy of your tax return in TurboTax Online: How do I print/save a copy of my return in TurboTax Online?