I moved from another country and was hired in Canada in April. How do I enter income from employers in other countries from January to March?

When you let the software know that you didn't live in Canada for the full year, then it will ask you for the income you earned before you became a resident.

Do I need to enter my income before becoming a resident by converting it to Canadian dollars at the average rate for the month I earned it?

Yes, you need to convert to Canadian dollars, but you can choose what rate to use.

Thank you so much for teaching me.