C6300 model: pressed reset button and now our computer tv etc can’t connect

Wi-Fi went down so my partner pressed the reset button on the router. She didn't know she could just unplug power chord. Now it reset back the netgear name and we don't know how to change it or change the password. Some of our laptops won't reconnect now. Some somehow stayed connected even with a new router name. How do we reconnect our devices and change back the router name and password