Wow, that's the longest sentence I've ever read!!
Since my trailer did not come with a TV, I cannot give exact advice.
I do suggest you make sure the TV is in the correct mode.
IE- do you have a button on the remote labeled "input"??
Try pushing that.
Does your TV work with antenna?
When you try to watch a DVD are you still seeing broadcast channels
or does the TV go blank?
Maybe others can suggest more specific things to try.
Your dealer is your best bet.
They should be able to show you how to use the system or discover
that it's not working and fix it.