I am looking for some home wifi education

You can connect another Nighthawk or Orbi system to your modem:

https://community.netgear.com/t5/Cable-Modems-Routers/What-s-the-Difference-Between-a-Cable-Modem-and-Cable-Modem/m-p/1864698#M21950

Your ISP Modem already has a built in router and wifi. This would be a double NAT (two router) condition which isn't recommended. https://kb.netgear.com/30186/What-is-Double-NAT
https://kb.netgear.com/30187/How-to-fix-issues-with-Double-NAT
Couple of options,
1. Configure the modem for transparent bridge or modem only mode. Then use the Orbi router in router mode. You'll need to contact the ISP for help and information in regards to the modem being bridged correctly.
2. If you can't bridge the modem, disable ALL wifi radios on the modem, configure the modems DMZ/ExposedHost or IP Pass-Through for the IP address the NightHawk or Orbi router gets from the modem. Then you can use the Nighthawk or Orbi router in Router mode.
3. Or disable all wifi radios on the modem and connect the Nighthawk or Orbi router to the modem, configure AP mode on the Night hawk or Orbi router. https://kb.netgear.com/31218/How-do-I-configure-my-Orbi-router-to-act-as-an-access-point and https://www.youtube.com/watch?v=H7LOcJ8GdDo&app=desktop
https://kb.netgear.com/26765/Disabled-Features-on-the-Router-when-set-to-AP-Mode

I would try option#2 or 3 first with nighthawk or wifi mesh system. 

Any Wifi Neighbors near by? If so, how many? Can use a wifi scanner to see whos around you:

https://itunes.apple.com/us/app/network-analyzer-lite-wifi/id562315041?mt=8
http://www.nirsoft.net/utils/wifi_information_view.html
https://www.acrylicwifi.com/en/wlan-software/wlan-scanner-acrylic-wifi-free/
https://lizardsystems.com/wi-fi-scanner/screenshots.php
http://nutsaboutnets.com
http://www.metageek.com/products/inssider/
https://www.sandman.com/knowledgebase/cordless-wifi-rfid-troubleshooting

Interferences from other wifi sources can cause problems.