Selling first removes financing risk. You know your exact proceeds before you make an offer on the next house, so there is no chance of carrying two mortgages or scrambling for a bridge loan, though it can mean a period of temporary housing if the timing does not line up.
Buying first protects you from a rushed move but adds risk. You are relying on your City Park house selling for what you expect, at a price that supports the new purchase, and a lender will look closely at your ability to carry both properties if there is any overlap.
A lawyer coordinates possession dates on both sides through the Information Services Corporation title system, so the practical answer usually comes down to how tight that overlap can be made. Get your hand-reviewed valuation from Joel Dyck.