You might start by learning about patterns,hoses, in painter and how to make them. Then design a pattern that is abstracted like you want then using several layers , create the look you like.
It will take some time to get a feel for this so start small and practice with concepts until you have a handle on how things come together. Like any medium, it takes some time to learn what does what.
You can also place photographs onto an existing painter canvas that is a photo of some abstract that you have found.
Hope this helps Wyndham