The cable you pictured in post #10 with a male to female is ideal for the Terrestrial UHF TV input. The plug bit can probably be prised out with a thin screwdriver. They can grip very well as evidenced by the old lead which was destroyed while removing it. Twisting/rotating the connection when inserting/removing usually advisable!
You also need a
F-plug to F-plug satellite lead to allow use of the Satellite feed on the LG TV (should you want it). This may give you additional channel choices compared to the terrestrial signals.
Finally, if you get a TV for the bedroom you will need to sort out a way of feeding the UHF TV signal to the 'return' socket on the wallplate you have pictured. (The return socket feed on to single plates with an identical socket in other rooms. Triax (a manufacturer of antenna parts) make a device to do this called a '
Triax Outlet Link' which you might find in the flat somewhere (they were often supplied as part of the original installations, but frequently go missing). Those rooms
will need a male to male TV plug cable!