I just bought a orbi nbk752 router and 2 satellites

i have done the factory reset on the router and satellites, i do not have a modem? mine is used with a sim card..  i do not have a nighthawk router.

i have done so many resets however i will try what you have mentioned.. if i clear and start from scratch which i have done and my email is connected to all the netgear items orbi and the app plus my tech support for a year along with my armor.. I have done the whole from scratch thing and that is when my netgear armor subscription that i paid for at check out got all screwed up. 

So what should i do about that? 

sq ft 3000 so. my orbi system will do 7000 sq ft total 

25 ft from satelite number 1 sitting behind my computer

approx 40 to 50 ft from router down the stairs to our sons bedroom basement

 our house is brick a ranch style family owned home built 1979

so since we were having so many issues we thought about using ethernet cables and we did that both satelites are now connected by that cause i thought it would help. but at this moment i don't know what it right from wrong.. i didn't know you were supposed to do the updates with a computer connected with an ethernet to router..