need help with painting from reference

[Rachael C]

Hi everyone! I'm new to painting (and crimson daggers btw),
I've messed around with paint like once a month for the past year and never really got much guidance.
I would appreciate it sooo much if someone can suggest painting practices!
(photo attached as a file)


this took around 2.5 hours. acrylic.
I've started on Kevin McPherson's "Fill you oil paintings with light and color" but I'm not so inclined to use his method of reading colors...
This is one layer of paint, painted from darkest to lightest.
Should I do some kind of under-painting?
Are there any other painting books I should pick up?

Thanks so much!