Freeview is digital signal through terrestrial signal (uses a standard aerial).
Freesat is digital signal through satellite so you need a dish. I run Freesat through the Sky dish. We renew / end our Sky contract every 12 to 18 months. You can buy your own dish but they tend to be quite big for some reason.
Standard TV uses Analogue signal that uses up alot of bandwidth and is transmitted terrestrially, you will need a Freeview / Digital receiver to decode the signal through your aerial that can handle both, as can the Coax cabling. Think of the difference between CDs and Vionyl / DVDs and Video.
‘Digital’ aerials are apparently a con, although if you live in an area of weak signal a ‘high gain’ (same thing) aerial may help, but unless you live in the sticks or a funny valley nothing more than a little ‘tweak’ may be needed to sort out your signal issues.