I tried pairing my iphone 13 pro max to the apple watch and it says unable to check for update, checking for a software update failed because you are not connected to the internet. Even though I am connected and I rebooted both my iphone and watch.

Hello suegu97,

Welcome to Apple Support Communities!

We want to help you get the Apple Watch updated and paired to your iPhone again.

We see you viewed the Apple Support page for Update your Apple Watch - Apple Support

From the link, we want to confirm you took these steps:

"Need more help with updating?

Try these steps:

1. Make sure that your Apple Watch is connecting properly to its charger. 
2. Restart your Apple Watch.
3. Restart your paired iPhone.
4. Try again to update your Apple Watch.

If the update won't start:

1. Open the Apple Watch app on your iPhone.
2. Tap General > Software Update.
3. Delete the update file.
4. Try again to update your Apple Watch.

Learn what to do if you see 'Cannot Install Update' when updating Apple Watch or if your Apple Watch says you need more available storage to install a watchOS update."

We hope this helps to further isolate and resolve the issue causing the error.

Cheers!