It sounds like the set is not receiving a TV or recorded playback signal, and wants you to be watching "TV" instead of being online when adjusting picture settings.
Possibly the set comes up in the internet or smart online mode instead of the TV mode. But since you can't connect to the internet, you are not seeing the icons for Netflix, YouTube, etc. Find a menu item like General, Setup, etc., and look for a setting to stop it from defaulting to the online/smart mode, but to simply come up as a TV when you turn it on.
When you get the TV part working, then you can work on the internet problem