Run the numbers on rent against expenses using the Residential Tenancies Act, 2006 as the framework for any existing lease you would be taking over, since that legislation governs what you can and cannot change about tenancy terms after closing.
A pre-purchase home inspection, typically $400 to $600, belongs in the process before you finalize an offer, not after, because deferred maintenance on an income property compounds faster than on an owner-occupied house since repairs also mean lost rent.
Spreadsheets and online tools model the numbers you already know; the harder part is confirming the numbers you do not. Get your hand-reviewed valuation from Joel Dyck.