Retirement income is reported on a form 1099-R. Since you won't have that form for your Canadian retirement income, you will need to enter a substitute form 1099-R in TurboTax.
Your gross pension income is reported in box 1 and the taxable amount goes in box 2. You will need to choose an appropriate code for the type of distribution for box 7.
Deluxe TurboTax would be your best choice if you are going to download TurboTax to your computer. If you are working online, you can start with the free option as you will be upgraded as is necessary when you go to enter your tax information.