Hi Eddie,

If you have lost your network settings, this could have happen due to two reasons:

Reason 1. Your WiFi Username and password or many be one of them has been changed recently and your iPhone is not able to connect with its old username and password combination.

Reason 2. Your iPhone has forgotten the WiFi connection from its saved networks or may be accidentally deleted by someone.

For the First reason, you can try resetting the password of your Router by simply doing the below workaround:

Default username & password
You may try default username and password. While not the same for all routers, it may grant you access. In many cases, the default username and password for a router is the following.

Username: admin or administrator
Password: <Blank>, admin, or password

Resetting the Router
If the default username and password are not working, it has probably been changed at some point in the past by you or your network administrator. Most routers have a small pinhole button on the back or bottom.
Pressing and holding this button for 10-15 seconds hard resets the router. This action restores all default settings, allowing you to use the factory default username and password.

For the second reason, try connecting to available Wi-Fi networks:

1. Tap Settings > Wi-Fi, and make sure Wi-Fi is turned on. Your device will search for available Wi-Fi networks.
2. Tap the name of the Wi-Fi network you'd like to join.
3. After you've joined the network, you should see Connected next to the network, and in the upper-left side of your display.

I hope this helps.

Regards,
Lokesh