Can I setup payment to charge in Canadian Dollars and US Dollars?

Unfortunately, you can only use 1 currency per payment form. However, you can have multiple payments in 1 form. So you can create another form with a different currency and then embed it on the current form. Please refer to this guide: http://www.jotform.com/help/161-How-to-Update-the-Multiple-Payment-Form

You can also use these widgets:
Currency Picker - http://widgets.jotform.com/widget/currency_picker
Currency Converter - http://widgets.jotform.com/widget/currency_converter

Hope that helps. Thank you.