Its almost always through personal connections or word of mouth/referrals.
The primary concern for small to medium business is if the consultant being hired is actually capable of providing the service they are claiming to provide.
Hiring someone off of an online ad, cold call, etc. is just unnecessary risk. They'd happily pay more when they know that the output is going to be what they expect.
"Fair play" in mystery novels means the author gives you all the clues up front, so you have a shot at solving the mystery just like the book's detective.
Events are considered high risk by payment processors because the nature of events is that you sell the tickets before the event (ie. you accept payment without providing the service).
Shopify focuses more on people selling physical goods (traditional ecommerce), so maybe consider a platform that caters specifically to events/services - maybe something like woocommerce?.
I strongly suggest you remove that. It's one thing to get inspiration from another site - another to completely steal someone else's work.