ax5700 says device offline cannot get to anything

AX5700 is a speed, not a model. 

What router do you have? 

Firmware on that router?
What modem/gateway are you conneting it to? 

If you directly connect to the modem/gateway, are you online? 

There's a minimum of info we need. We much prefer more info to less because we're not there to see what you've done, what the issue is, and much of anything. so help us to help you. 

If you visit the support pages:

Support | NETGEAR

you can feed in your model number and find the documentation for your hardware.

Check the troubleshooting section in the manual. If that doesn't help, come back with some answers to the questions from plemans.