Watercolors are one of the oldest kinds of paint. Did you know the ancient cave paintings were made with watercolors?
They are also easy to transport, easy to clean up, and easy to blend, making them one of the most versatile paints to work with.
A great place to start: try making a line first, and then adding water on top to see how it spreads. Next, make a shape with water, and then dip your painted brush into it.