If I only install the USA World UP and no other addons, about how much space would FS 2020 need on the hard drive. I am just doing VFR with a small plane in the USA
Assuming you only install the POIs and scenery, it can’t be bigger than 120GB.
You should also go into the Content Manager and remove the planes you don’t fly, and if you aren’t interested in them, things like the Landing Challenges, Training and Discovery Flights. It all adds up.