Hi Iphoneusers7,
Thanks for posting in Apple Communities.
We understand that you're unable to activate iPhone. If you're unable to connect to a different Wi-Fi network to activate iPhone, you will need a computer to complete the activation.
1. Restart your iPhone or iPad.
2. If you're using a cellular-data connection, connect to a reliable Wi-Fi network instead.
3. If you get an error message on your iPhone or iPad that says the activation server is temporarily unavailable or cannot be reached when trying to activate, wait a few minutes, then repeat the previous steps.
If you still can't activate your iPhone or iPad, try again using your computer instead:
1. Make sure that you have the latest version of macOS or the latest version of iTunes.
2. Check that your computer has an internet connection.
3. With the cable that came with your iPhone or iPad, connect your iPhone or iPad to your computer. Locate your device on your computer.
4. Wait while your computer detects and activates your iPhone or iPad:
-If an alert appears that says "Set up as New" or "Restore from Backup," it means your iPhone or iPad is activated.
-If you get an error message on your computer that says that the SIM card isn't compatible or is invalid, contact your carrier.
-HT201407If you get an error message that says the "activation information was invalid" or "activation information could not be obtained from the device," use recovery mode to restore your iPhone or iPad.
These steps can be found in If you can't activate your iPhone or iPad (Wi-Fi + Cellular).
If you do not have access to a computer, it would be best to find a nearby Apple Authorized Service Provider where you can activate iPhone.
Regards.