First time propagating – What do I do now?

This is my first time successfully (I think) propagating plants, my mum gave me some cuttings from her house plant and I've had them in water for quite a few weeks now. I've been changing the water and now I think they're ready to plant, are they? Should I cut off the excess stalk below where the roots have grown?

Should I use a specific kind of potting mix or fertilizer? I have a liquid seaweed fertilizer that I use for my other house plants but I was told by a garden center worker that I shouldn't fertilize newly propagated plants.

I'm surprised it's gone so well up until this point when I've been completely winging it, I don't want to mess it up now! I also am not entirely sure what plant these are, maybe a mini monstera? The leaves are quite small.