If anyone needs any extra information/help regarding booking airline tickets i will be happy to help
you can inbox me.
Some flight options to consider are:
PIA direct to Canada (3 days/weekly)
Turkish via Istanbul to Canada (6 days/week from KHI and ISB)
Emirates/Etihad (3 days a week to Canada via Dubai or Abu Dhabi)
One way prices from Karachi are looking to be around $1500-1900.
it is always best to book your ticket as in advance as possible, but i recommend to wait for your Passport with visa first! 8)