First Time Using a Mobile Mechanic for AC Repair

I’m looking for mobile AC repair services in Florida for my car. It’s my first time dealing with mobile mechanics, so I’m not too sure what to expect or how to go about choosing the right one. I’ve done a bit of research and listed a few options, but I’d really appreciate advice from those with hands-on experience in this area.

What should I look out for when selecting a mobile mechanic for ac repair? Are there specific certifications, tools, or skills they should have for AC repairs? Also, how do I ensure I’m not overcharged or scammed? Should I ask for a warranty on their work or specific estimates before they start?