Basic: There are four (4) brushes available in Animation Desk, along with an eraser and a color filler (bucket).
Advanced: All the brushes and the eraser come in five (5) patterns each. If you are a subscriber to Creativity 365, you will have access to all of them.
Double tap on any of the brushes to choose pattern.
To change the color of your stroke, select from the colors under the brushes. To access more color, choose from the color palette.
Expand the Brush tool bar by tapping on . You can adjust brush size and opacity from here.