Get a few basic acrylic colors and paintbrushes and start painting.
As a beginner in canvas painting you may feel overwhelmed when starting a project. There are many directions you can follow, but it's easier if you make a plan and cover the basics. Having no drawing experience doesn't mean that you can limit yourself to non-figurative art; you may experiment painting the human portrait as well.
Paint a Replica
Painting a replica is a study of colors and shapes that may help you in the future painting projects. Choose a famous painting that you like and try to create a replica to get a feel for the colors, paintbrushes and their strokes. You may do a freehand drawing on the canvas or use tracing paper to copy and transfer the drawing from an album to your canvas. You should look at each area of the painting and think about the colors and strokes the painter used and try to obtain similar colors.
Abstract Art
Abstract art or non-representational art is always a good starting point for beginners in painting. Even if there are a few rules in abstract art as well (e.g., composition, color matching) you may use your intuition to create your abstract art. Start from a scenery or a portrait and stylize it to obtain an abstract composition. You may also start from simple geometrical shapes, which you can combine and color.
Still Life
Still life is suitable for beginners and you can arrange a few items on a table to paint after them. For your initial projects, choose items of completely different shapes and sizes that have vibrant colors. For instance, arrange some flowers in an unusually shaped vase. Try to use a few basic colors to obtain the shades that you need, so that you get acquainted with mixing colors. For instance, you can obtain green using yellow and blue, then use black or white to shade or tint it.
Portrait Painting
When painting a portrait you don't necessarily have to adhere to a set of rules. If you are a beginner, it's easier if you simply paint a portrait using the skills you have: observe your model and use colors to depict the portrait. A portrait doesn't have to be drawn realistically to be esthetically pleasing; the portraits of Modigliani or Basquiat (see Resources) are proof of that. When studying the model you want to paint, find a characteristic that makes the portrait unique and base your portrait on that, or you can even exaggerate it.
Use Acrylic Paints
Acrylic paints are more recommended for beginners, because they are easier to handle than oil paints and they also dry quickly. Mix your colors on a glass palette and dilute them using water. These paints are suitable for creating all types of paintings from abstract to figurative. Acrylic paints can be applied in a thin, transparent layer or you can obtain a few textured effects by applying thicker layers of color or by mixing your colors with sand or gravel.