Hello qtonik123,
Thanks for visiting this thread.
Your case is that of a double edged sword. You have two options.
1. Safer option:- I would suggest the following, get your admission and fly to Canada on the tourist visa. Before you fly contact a good immigration lawyer and ask on the process of how to change conditions from visiting to study permit, infact start that process now. That way you are already in the country and the chances of your tourist visa being cancelled is far less.
2. Right but Risky Option:- Get your admission, apply for your study permit, justify why you are just applying for a PhD at this time and hopefully you get your study permit. Bear it in mind that with the volume of application the embassy is getting coupled with the socio-political tension in the country, Canadian visa study approval rates as at 2017 was less than 15%, I don't know if it has come down further since then as they have not released the data.
These are my honest opinions. Please take them with caution, ask God for guidance in all you do.
Wish you the very best.
Omofar