Taxes have to be paid, so does insurance, what about maintenance? 

My biggest conundrum now is I want to be my own GC because even when I play with smaller numbers they’re still out of reach for me to be able to attain this goal and afford the monthly mortgage with taxes and insurance.

A few others have called out Hemlane, who appear also quite responsive here on BP and also offer a degree of repair/work order management baked right into their middle/upper tier offerings (versus having to bolt-on as with RentRedi + Latchel). 

Did you walk the property before offering?

He offered to sell it to me with owner financing for $400,000 and only required 10% down, so I jumped on it.

The cost associated with insurance for not having 20% is peanuts compared to what you potentially can do leveraging your down payment. 

Adding your property manager as an additional insured means they will be listed on your insurance policy as a named insured.

Just remember if you want to purchase another one you will need to refinance at an 80% LTV as you can only have one CMHC insured mortgage. 

They had listed it for $40k more in 8/24 and dropped consistently until 12/24, when I made my offer.

You can even connect with local HR teams and offer small referral bonuses to get more bookings.