Somewhere on the back of your regular tv will a sticker listing manufacturer and etc.
Have a read and find the power consumption. It will be a number of watts. Our tv/dvd pulls about 20 watts.
Then you need an inverter to change 12 volts into 220 volts.
For example Halfords sell an 150 watt inverter for €40 ish which can be plug into a cigar lighter, just make sure that its a leisure battery conection not an engine battery.
Finally for ariel signal. Assuming that your tv is saor view or free view ready, the cheapest option is to get a standard chimney ariel €20/30, strap it to a long handle or pipe, and when you park up cable tie to your rear bike rack for signal. A top of range, self finding satellite system will set you back a couple of grand. There is a roof mounted type of ariel available.
Alot of folks now watch tv on a laptop linked to their phone data signal.
Food for thought,
Malcolm