Hi Ravi! Congrats! ;D
You haven't specified your nationality, from your name, I'll assume you are South Asian.
If you are an Indian national and are flying to or from Canada on a valid Canadian visa (SW1 visa) you do not need a visa to transit Europe (London/Frankfurt/Amsterdam)
If you are a Malaysian national, you can visit and transit Europe visa free.
If you are a Pakistani/Srilankan national, you will need an airport transit visa to transit Europe even if you will remain airside while transiting in the airport.
If you are any of the above nationalities and transiting the US, you will need a US-'C' Transit visa.
If you are a Singaporean national, you do not need a visa to transit/visit Europe or the US.
Not sure about South African nationals...
British Airways, KLM, Lufthansa and Air Canada all fly from the middle east to Calgary at competitive rates.
I paid $1200 approx for an August round trip from Kuwait to Calgary.
Good luck!! 8)