I hate to be the poster to burst your bubble, but FistMed isn't a primary 911 responder...not sure where you got the Ling Beach part, since a cursory check of FirstMed's website says nothing of that sort, only that they do national level disaster support after being activated by FEMA....so don't get burned out expecting to do 911 calls all day long and instead find yourself doing hospital discharges, doctors appointments, dialysis, etc calls instead. In fact, IFT companies, IMO are great place to learn general ambulance operations, interacting with real patients, touching them, assessing them, doing vitals (it's one thing in class to check the BP of your 20 year old classmate calmly sitting next to you, completely different on 90 year old grandma in the back of an ambulance filled with road noise bouncing down the 405...) reading/writing reports, interacting with nurses and all other health care providers at multiple levels in and out of the hospital.....etc etc
So to get my derailment back on track, unless they specified itherwose, Business Casual for the interview with a change of gym type clothes for the lift test (I once showed up in a suit and tie for an interview, got surprised by the, "ok, we're gonna do the lift test right now" and took off my coat and tie and still passed it without ripping my suit pants lol)