Do I need to report my 90-day stay after changing my visa from a tourist to a Non-B in a different province?

You have not had a stay that can exceed 90 days yet, so you are not subject to 90 day reporting.

Even after you convert to non-B visa, that is only a 90 day visa and not subject to 90 day reporting.

When you go to get your first 1-year extension based off work from your non-B, they will put a piece of paper in your passport that will give you your first 90 day reporting date. Because the 1 year extension will be the first stamp you receive that allows you to stay more than 90 days.