US taxes its citizens/residents  ( green card holder  or  aliens  whom have met the substantial presence test ) on world income and gives credit for taxes paid to another country.

So you have to file US return covering only US income ( if you had not the substantial presence  during 2018) or world income if you had become a resident / resident for tax purposes.

Equally you will need to file a Canadian tax return per Canada's tax laws.

TurboTax prepares only 1040 series returns ( US citizens/ residents/ residents for tax purposes ) and not  1040-NR series ( Non-resident alien with US income).

TurboTax will ask questions about treaties but s generally not geared towards raising and  resolving  treaty issues / conditions ---- this is generally aimed at US taxpayers with generally US sourced income. It work pretty well for US taxpayers whom are expats.

Is there something else I can help you with?

i have W2 and Canadian T4, can I do with Turbotax?

If you are a US citizen or resident, you are required to report worldwide income including the Canadian income on your US tax return Form 1040.  As far as your Canadian taxes, you will have to check with the Canadian tax authority for the filing requirements.  To file your Canadian return, click here: TurboTax Canada

The income tax treaty is out of our scope for advising purposes.  You might need to consult a tax attorney or tax professional who is specialized in this aspect. 

@droletjason

Yes, if you are a US citizen or resident, you can file with TurboTax.  You will be required to report worldwide income including the Canadian income Form T-4 on your US tax return Form 1040.  As far as your Canadian taxes, you will have to check with the Canadian tax authority for the filing requirements.  To file your Canadian return, click here: TurboTax Canada

To enter a Canadian form T-4 in the program, first to convert Canadian dollars to the US dollars, then follow these steps:

In TurboTax online,

• Sign in to your account, select Pick up where you left off 
• At the right upper corner, in the search box , type in foreign income and Enter 
• Select Jump to foreign income 
• Next screen, Did You Make Any Money Outside the United States? answer Yes 
• On screen, What Form(s) Was Foreign Income Reported On? Select a statement from my foreign employer
• Follow prompts to enter info

To enter your From W-2, here are the steps:

• At the right upper corner, in the search box, type in "w2" and Enter
• Select "Jump to w2"
• Follow prompts

 @jamesmansour01