Get a referral - you should talk to people you trust and ask who they used and what their experience was like
Ask about their qualifications - what certifications do they have? Are they an engineer? How long have they been doing this? How many inspections do they do a year?
Ask about their fee - fees in the Kitchener/Waterloo area are typically in the $400 - $600 range
Ask if they carry errors and omissions insurance
Make sure you can be present during the inspection - if the inspector says you can’t be present, walk away. Being at your home inspection is critical