Need tips for Mammoth Cave trip next week (!)

Months of anticipation, now it's upon us and we are NOT prepared with any information. Any tips and info would be MUCH APPRECIATED!

Looking to visit Mammoth Cave in Kentucky next Wed eve for about 3 days or so.

Anybody been to the cave? Tours? Handicapp accessible (limited walking ability, or we can push in a wheelchair, depending)?

Best tours to take? Close/nice site with AC and optionally water?

We are taking an older couple with us with a hip replacement, bucket list stuff, probably one of them will want to go on an abbreviated tour with limited difficulty and walking, but then want good electricity and comforts for her at the camper while the rest of us go back to the cave.

No pets, no smokers, etc here. Though we don't mind parking in pet areas, either.

Are there tour times, self-tours, private tours? Any touring companies? One better than others, etc?

My family is going to continue from there to Crater of Diamonds in Arkansas, the other four will return home from there.

Got a tip or info, please share it! If your itineraries or plans were/are private, PMs are okay, too :)

Thanks!