It's not quite that basic.
Before more is discussed I suggest you think twice about doing this yourself as a first technical TV project for you, it requires things like careful alignment of the LNB and that done without disturbing the dish's alignment, checking the condition of the cables and connections, not over-tightening those, waterproofing, rewiring to your out building, keeping the heartbeat (HB) connection in place, and so on.
More than possible for you to manage with and you could even end up enjoying doing it
, but not a simple task.
If you do decide to, just say so and I'm sure there will be further help on hand from others in the next few days.
But then best to wait for Geoff D to add his experienced advice.
I'm going to stay out of this one, really can't afford the time investment.