If you are an absolute beginner I would watch some of this guys videos
https://www.youtube.com/user/DrawMixPaintIn particular 'How to paint in oil'. Then paint a few still lifes so you understand how to match colour. From there you can go a number of different ways, you can learn more about colour theory, perspective, human form, whatever. But first understand how to match colour and how to actually paint, go from there
