Do I need to stay in the province that nominates me for 2 years??
Regardless of the destination mentioned on your COPR, you can land at any port of entry in Canada.
If you are an FSW
applicant you can choose to mention any address or destination (except Quebec) when asked by the border officer.
Reasons
I would strongly suggest staying in the province for atleast the period, until you get your PR cards and then after having tried to settle in the province, move if you have to.
Some email queries to Province Authorities and IRCC on this subject has been replied with the same response that, – You are free to move to any province once you have your PR cards, and that you are not required to inform any authority of your move. The responses also suggest residing in the province until you get your PR card.