Hi
I'm an University student (Asian holding F1 visa) working on my work and travel programme currently staying in the USA, I would like to visit Canada, do I have to issue visa at the embassy first or I can enter the US without problem?
Your post doesn't make sense, are you asking if you require a TRV (visitor visa) to enter Canada? It depends on your citizenship, or do you require a visa from the US to re-enter the US after visiting Canada?
PMM