For touring caravan many use a dish on a tripod at ground level, my satellite receiver has a built in audible satellite finder, so once the receiver has been tuned in which is done at home, using a spirit level to get azimuth then you only need to get direction and you turn until beep is loudest, first use you need azimuth normal is to set that at home so you can see direct dish needs to face and approx azimuth and once azimuth found then spirit level finds it when moved with just a small tweak as you go up or down the country.
However your talking about a static caravan, so dish is fixed as with any house, it can be at ground level does not need to be high, however clearly at ground level any thing in front of it can mask the signal. With the built in finder, or portable finder you can get the dish set up, but it is quite fiddly and at home I found it pays to get a aerial guy to visit with his box of tricks to set dish up, seems there is a group of satellites, not one, so if you set box to BBC 1 that channel may be A1 but you may not get whole range, I am sure
@Lucid can explain, but with their box of tricks, once set you get all channels, so I would say worth the money getting a local guy to set up dish.
The satellite boxes it seems come in two main flavours, free to air, and freesat, the free to air are normally cheaper, you can get specials that connect to motors on dish so you can tune in to many satellite clusters, but unless you are multi lingual then not much point, and the free to air often have a poor electronic program guide, you can get all the programs, but you need a TV times to find out what's on, some will give a limited EPG but not 7 day all channels you get on Sky. The freesat I am told does give full 7 day guide same as Sky.
TV size is also important, with a 14" TV SCART is fine, even a coax with RF will do the job, by time you reach 32" TV you see real difference between HDMI and other methods to connect, with 14" an old Sky box will give a good EPG and reasonable picture quality, but with larger TV's you really need HDMI to get reasonable quality. I use a IceCrypt STC3250CCIHD which is a HD receiver both freeview and free to air satellite and I can if the EPG works record to external hard drive, and watch all the free satellite channels, and more HD channels than I can watch with my Sky package, as not paying for HD. However I would not recommend it unless very cheap, the EPG lets it down, often have to select channels to get the guide to work, and lucky if I get whole 24 hours, getting a week is very rare. So really want a box which is freesat then told the EPG works well.