If you're talking about looking from the top of a hill, you'd probably use neither (sorry). "View" is better: "enjoy the view from the top of the hill". This implies looking from a particular place. You can use "outlook", just about, but as Alex says it's quite an unusual use of the word.
"Scenery" doesn't imply any particular act of looking, so you could talk about "beautiful scenery" whether you are looking up at it, looking down at it, looking at a picture of it: those would be different views of the same scenery.