Orbi AC2200 RBK30 working with Netgear N600 C3700 Cable modem

I'm not knowledgeable in this area. I'm setting up my new Orbi with an existing dual band Netgear Cable Modem. Does the Cable modem wifi interfere with the Orbi system? Is it better to turn the wifi off on the modem or run the wifi on the modem in one room and the Orbi router in another room. I wondered if they were in different rooms if the modem would help extend the wifi "mesh".
Also how do I set up the dual 2.4 and 5Ghz bands? with two separate network names or does each network cover both bands?  My Arlo system uses 2.4Ghz and 4k Fire TV prefers 5Ghz. I was reading somewhere some devices switch back and forth based on best available speed, Do I need to set up my network a certain way to achieve this?

Thanks for your sugestions!