Filing taxes in Canada is relatively simple compared to the USA. See the site for various options, but try to find ones not operated by American firms such as H&R Block and TurboTax.
From a cursory search, TaxTron, GenuTax, Better Tax appear Canadian. Many are Pay-What-You-Want model.
If you have a complex tax situation and/or can’t file online, and/or don’t want to do the paper return yourself, consider seeing an independent Canadian accountant.
I’ve been using Wealthsimple for taxes for 4 people for the last 3 years and it’s absolutely fantastic. Would recommend to anybody.
The fine print: up to 2 people can file for free, but they’ll ask for a “donation” when you get ready to netfile. If you have more than 2 people you need to purchase a plan ($40 for up to 8 returns).
Easy workaround: don’t have more than 2 people on a single Wealthsimple account and you can file for free again.
I do my parents’ taxes and it’s worth having everything organized under one account so I gladly pay for the plan.