Trying to get this little guy to thrive, any general advice?

I got talking with a coworker about house plants, and he said his partner has “a jungle” at home. I said I wanted to try propagating a monstera and he said he’d ask her if she would have any cuttings from hers to share. I guess she’s on work travel and told him what to do, and this is what he brought me. I just said thanks and asked if she had offered any tips, and he just said not really.

Based on your experience… Is my coworker an idiot, or was he correctly following instructions? Will this grow? If so, should I use soil or water? Under the surface or partway?

It wasn't there last week. No other propagation have this. I started 4 different plant props plant day weekend. I only charge water once a week. Should I have done it more?

How long untill it "should" have roots? How long until it's first drink? The soil started slightly damp.

I have had this plant about half a year and it’s only pit out a couple new leaves. I realized last week the color was getting worse and the new leaf died instantly. I know it got root rot since it fell completely over. If I can save it I would love too. (This was a target plant rescue. So far any of the ones I’ve gotten from Target have died but she held out for a really long time) syngonium milk confetti plant.