It may affect your traffic unless you're targeting mostly Canadians. Country specific domain names rank well if the searcher is in that country, but not so well for those living elsewhere.

.com is the most popular and can give higher ranking in Google, but .net, .is also good. .org is used mostly for organizations, charity sites, learning institutes, etc.

k .. thnx .. may have made a mistake but I got a .ca domain.. I went for good key word but couldn't .com ..

Dot com is preferable but .org and .net are also fine.