If no one hasn't said so already, welcome to EMTLife!
If you use the search feature you'll find tons of threads involving Lynch and Care, including many asking the same question as you, so those threads can be great places to get answers.
I personally haven't interviewed/tested at either company, but in my experience, the tests are basic EMT stuff. Same with skills. If you've passed your EMT course and the National Registry, you should be able to easily pass an employment test. Be prepared to explain what SAMPLE, OPQRST, DCAPBTLS, APGAR, AVPU, etcetera is.
As far as skills, I can't imagine it'd be any more complicated than stuff like opening an oxygen tank, inserting an NPA/OPA, CPR, Spinal Immobilization, splinting, etc.
Once again I can't comment specifically on Care or Lynch's process. I've interviewed at companies where it's just an oral interview and they'll call you back later, some where you take a written test, and then they'll call you back later for skills and interview, others where all they wanted me to demonstrate was cracking an O2 tank and placing an NRB on a patient, and others where all in the same day you'll take a 50 question written test, demonstrate pretty much all the NR skills for EMT, and then do an oral interview and finally get an offer on the spot if you pass. So don't be surprised if they want everything or only a quick test or not. I know, it can sound like a lot, but just remember as an EMT you can be called upon to perform any of your skills at pretty much any time without prior warning. But most places just want to see if you've retained enough info from class that they can train you up in their specific way of doing things in a relatively short time frame (without leaving you behind)
Common interview questions include, but are not limited to: "what made you interested in EMS? What makes you want to work for our company? What customer service experience do you have? What's your greatest strength and weakness? What would you do/ what have you done when confronted with an angry patient/family member/bystander? Interpersonal issues? Stressful situations? Juggling multiple projects?" Etc.
Personally I'd choose Care over Lynch. Care is a very well established, very well respected company that provides 911 response in large portions of both LA and Orange counties. To the best of my knowledge Lynch only provides non emergency inter facility transports.
