Click the Paint Brush icon on the main Toolbar. We are going to draw a very simple flower. I am not looking for priceless artwork here, folks, so don't be upset if you can't draw--I can't either! For now, I just want you to get a feel for the way some of the tools work and give you something to practice with until the next lesson.
Once you've selected the Brush tool, your Options bar should display the Paint Brush tool options as seen in the figure here.
Please note: Due to image width restrictions it was necessary for me to cut the Brush Options Palette in half in the screen shot shown here. The first part is #1 and the second half is labeled as #2.