So I got my first ever Swiss Army Knife 2 months ago. It’s a Victorinox Huntsman with 14 tools (the one with the saw). I have not used it extensively yet, but I wipe it clean every time I use it.
I’m not aware of when and how often I should oil the moving parts and things like that. I would like to keep this knife in working condition for as long as I can.
Not much honestly. Keep it away from dirt and dust, so in a drawer, glove compartment etc. other than that oil the moving parts and only re-oil when it feels like it needs it. Keep it sharp too, including scissors and saw.
One last note, if it gets wet, dry it before closing.