From the manual, it looks as if this TV has a Digital Video Broadcast (DVB) tuner fitted, which should pick up any MPEG2-based terrestrial DVB services operating in your area. Do you know if there are any?
To get high-definition (HD) TV you will probably need a satellite receiver and decoder that can connect to the TV via HDMI socket. There are terrestrial HD services here in the UK but you need a special tuner; nevertheless an ordinary standard definition (SD) tuner might recognise the digital stream but be unable to decode it.
Download the manual from here: http://www.superfi.co.uk/extras/LG/LG_42PG3000_manual.pdf
Your TV is listed as 32LG5***