Hi,
I am a recent PhD graduate from USA and currently on OPT and living in USA. I am going to get a postdoc offer from Canada and planning to move there. My question is what would be my status if the postdoc position doesn't work out in Canada and have to leave the job?

1. How many months can I legally stay there before finding another opportunity elsewhere?

2. Can I get back to USA?

I appreciate your response.

Thanks