Oh, thanks David!! Those are helpful! Honestly, I have NO clue about fingerings or positions because my last experience playing guitar was (quite literally) 40 years ago and nothing more than strumming.
My concern is that I know how easy it is to write something which is humanly impossible to play when you're working in a notation software, and so I just wanted to make sure I was avoiding that mistake. My orchestration book covers classical orchestra instruments including brasses and I have experience playing all the reeds plus flute and piano, so I'm okay there, but popular music instruments like bass and guitar are a little out of my wheelhouse. Really appreciate everyone taking the time to help me!!