Hi all, long time no post. Looking for critique and advice! I just picked up oils as I found acrylics drying waaaay too fast and an unforgiving medium for me

I haven't tried painting in a while, so this is a first in a long time. I seldom (well never) finish any painting, mostly due to frustration. Here goes.
I chose a composition by Merethe T from the image library - seen
here.
After reading many posts here I thought I'd try an underpainting to see if it would help me towards the end. Here is the beginning: (bear with me if I don't post correctly, and images are taken with a cheap camera)
More to come if this works...
