Hello 'girlteam',
<< I really need the Username of all the eBay sellers from Canada. How can I get this list?>>
You can't. Even if there were such a 'list', no one would give it to you.
For what purpose do you "need" it so desperately?
If you wish to shop with Canadian sellers exclusively (always a good decision) all you do is type your Search term keywords in to the Search bar and click the Search button.
Then, -- because it is always a 2-step process, -- from the left side of the page under Item Location
choose Canada Only.
From there, using the Sort bar you can choose, say, Time: ending soonest, or maybe newly listed, or whatever. Anything but 'Best Match' because half the time what comes up there does not even have any of your chosen terms in it.
This will show you everyone in Canada who is offering the items you seek at the time.
Unfortunately you cannot save these Search criteria as a permanent preference and will have to redo it every time you start a new search. Ebay reaaaallly wants people to buy American.
Happy shopping. 
