Canadian here, this isn't entirely accurate.
What you have to understand is that (formally at least), Canada is like Britain in that power and authority to govern come from the Crown and not from the people (again, in theory). Keep this in mind to understand the following:
The Crown in Right of Canada
The Queen is the source of all power, but she delegates it away to different people and groups. The Governor-General (President in the above analogy, but he has very few real powers, mostly reserve) is the representative of the Crown in Canada and acts on Her Majesty's behalf. As his name suggests, he's the Governor and so exercises the Crown's will in Canada (he's also called General by contrast to the representatives of the Crown in the provincial governments, which are called Lieutenant Governors).
Canada has a separation of powers into legislative, executive, and judicial just like the US:
The Queen (represented by the GG) is 1/3 of our legislature, called Parliament. The other two parts (based on the British model) are the House of Commons and the Senate (equivalent to the House of Lords in the UK).
The HoC has members, each representing a riding (electoral region) in which the residents choose their Member of Parliament. De facto, the HoC is the most active and powerful part of parliament. The Prime Minister and his Cabinet of ministers is chosen by the GG from the House of Commons.
The Senate is the upper house of parliament, but it barely does anything. It has members appointed by the Queen via the GG (on the advice of the Prime Minister, we'll get to that later). Members are appointed pretty much for life (they have a mandatory retirement age).
For any law to be passed, it must be approved by all parts of Parliament. In practice, most laws originate in the HoC and then the old farts in the Senate pass it and the GG signs the bill on behalf of the Crown, signing it into law.
The GG (representing the Crown) chooses a Prime Minister as well as other ministers from the HoC to act as a national government, which creates policies etc. In practice, the GG chooses someone who will have the confidence of Parliament, aka someone with a plurality of seats in the GG (since we have 3 major parties it's possible to have 'minority governments', when the ruling party is the minority in the HoC). The Prime Minister is the Head of Government and is in practice the most powerful figure in Canada (supposedly he has more power in Canada than the POTUS in the USA). He has the power to "advise" the GG, which means the PM basically writes down a list of people he wants for the Senate or judges and the GG will approve them. Since the GG also is the one who calls elections, the PM can "advise" him to do that as well. Basically, the PM can do practically anything in the current state where the Crown under the GG is 100% cucked.
As mentioned, Judges for the Supreme Court of Canada are appointed by the GG "on the advice of" the PM, which means in reality Canada does't really have a proper separation of powers.
I didn't mention the governments of the provinces (which also have Lieutenant Governors and Premiers and Supreme Courts which act similar), and there is a complex interaction with them since (unlike in the US), our provincial governments have defined powers by our constitution. Hopefully this gave you enough of an understanding of how our government works.