Learning How To Paint

For the past few months, I have been messing around with photo-manipulation in Photoshop. I've spent a lot of my free time creating mashed up images of landscapes and architecture that I found from random photos around the internet. But using existing photos to create an image really limits the imagination. It made me want to learn how to actually paint, so I've decided to learn how to paint digitally. I've never painted traditionally before so the whole idea of painting is new to me.

Below are some of the pieces that I have done in the last month. My intention is to create an overall mood with the painting and not worry too much about details. They are very beginner level and I would heavily appreciate any feedback. 

If anybody is familiar with drawing or painting and you have any advice for me, I would love to hear it. Thanks!