This is a really great start! You have all the momentum here.
I would note one thing though, that cliff being so big at the one end, it feels odd how flat the coastline going on above it seems. Maybe add a little area where the cliff continue, but much smaller closer to where that North Western river comes out. It might just give the effect of the cliff shrinking that side. (Just a suggestion)
Hmm, I'm with PaperGriffin on the open space, on one hand it is nice to fill in some of it. But, then you also want to keep some in one way or another as plains or such.
Anyway, if you want to fill in some stuff, here is a grass brush I made and used for my Sambria map. You are welcome to use it, it is very simple.
Grass_Free_v1.png
I look forward to seeing you progress. You have a head-start in my view.