This is my first Quebec return. Therefore I don't have a prior year's notice of assessment. Does this mean I can't file it using Netfile?

You don't need the number from your prior year Notice of Assessment to submit your return to NetFile Québec.

TurboTax prompts you to enter your Notice of Assessment number from your prior year return if you choose to:

• Change your address
• Set up or change your direct deposit info
• Import your slips from Revenu Québec directly into your return

If you need to change your address or set-up/change direct deposit info with Revenu Québec, you can do this on the phone with them before you file. 

http://www.revenuquebec.ca/en/sepf/services/sgp_adresse/default.aspx

http://www.revenuquebec.ca/en/citoyen/declaration/payer/remboursement/depot_direct.aspx