Sue, the clue is in the name - FreeSAT ! It gets the free channels broadcast via satellite. It uses the same signals and satellites as the Sky service (using the cluster of Astra satellites at 28.2 degrees East) but just the free to air ones, not the subscription ones. If you already have Sky then you can use your Sky dish - if not then you need a dish installing. Contact any local aerial or Sky installer who can do the job of putting up a dish for you.
I'm guessing this is a Panasonic Viera seeing as they are the only TVs released so far with a FreeSat tuner built in - very good choice (if I may say so) I'm sure you will be pleased with it.