Yes and yes...
I'd exchange to Jamaica dollars. Not sure where you're from, but US dollars are widely accepted, and I believe CAD are too, there are many reasons to exchange- primarily, you are in jamaica, so use Jamaican dollars.
While credit cards are widely accepted at many hotels, restaurants, and bars, credit card fraud is a ceoncern, as it is everywhere, so be certain to ensure your credit card has a zero or limited liability policy in case of fraud, and be sure to monitor your statements carefully for many months.
I prefer to use cash whenever possible. I have not had any problems using the scotia bank ATM at the roundabout to withdraw cash. That said, you could have the similar fraud concerns wi an ATM machine, so monitor closely if you must use a credit or debit card of any sort.
