https://www.newschoolers.com/forum/1453/Build-A-Jib-101
A whole forum dedicated to these things. Not so active anymore but you can find a bunch of information. You can also learn from what people did that worked, and what failed. Could save you some hassle.
As far as your post there are a lot of factors. Space, do you have a hill, budget, etc.
If you don't have a hill youre going to need to build a drop in. Lots of pictures and plans in that cult i linked.
If its strictly for winter use the drop in can be smaller and you dont need to buikd an inrun and jump.
Pvc rails are super easy to build. There are several tutorial threads in build a jib.
As far as a jump, if you dont have a hill its just not going to work. Unless you buikd a drop in ramp off your roof or something.
Salt is only helpful with wet snow. When its warm and the snow is wet you throw salt on it and it will freeze fairly solid. Great if you're setting up a street spot or backyard rail in the off season. Instead of having to keep throwing snow on tbe in run and rebuilding the takeoff, the salt will keep it solid. Also very helpful for keeping speed which is the main issue in backyard park action.