I have an Apple Air 2 iPad that was reset to the factory setting and I can't get on as it says it is because the activation server cannot be reached. what do I do?

From your description, I infer that your iPad does not indicate that it is Activation Locked.

As an alternative to direct activation from the iPad itself, you might try activation by connecting the iPad to your PC (with iTunes installed) or a Mac (with iTunes or Finder).

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 iPad, connect your iPad to your computer. Locate your device on your computer.
4. Wait while your computer detects and activates your iPad:

• • If you see an alert that shows "Set up as New" or "Restore from Backup", it means your iPad is activated.
  • If 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.