One of many valuable lessons that I learnt from my studio teacher was not to over-think the process. I experienced a big canvas scare at the beginning. I was armed with paint and brushes but could not start painting. I spent lots of time staring at what was in front of me and was very indecisive on what colour to use and what to paint in general. The feeling was almost paralyzing.
My advice to you is to paint nothing. Do not concentrate on possible virtual images that you are trying to find within. There are so many, and they will all come along at their own pace. For now they are just putting you in a state of confusion. Redirect your attention to colour. Get your prime colours and start mixing and matching. You will start learning how to create different colours and shades with only these three colours. It will give you a great deal of understanding on how the colour works. To help you with this divine process, the one tool you absolutely must get is the colour wheel, which is available in every art and craft store and those stores that have art and craft department. A colour wheel is basically a map of relationships between primary (yellow, red, blue), secondary (orange, purple, green), and complementary (opposites: ex. red and green, blue and orange) colours. Use this illustration to practice colour: if you want to create a tint of a colour add white, to create a shade add black. Follow the paint, play, and experiment with it then observe the results.
With all that said, what you have to remember in this fun and exploring process is that acrylics are a quick drying kind of paint. You can prolong the working paint time by wetting your canvas with water using a spray bottle. Just sprinkle a little bit on a canvas, moist will keep paint from drying. I use this trick all the time.
So get the paint and put that first colourful mark on a snow white untouched canvas, see where it takes you, possibilities are endless. Have fun!