Oekaki is an in-browser drawing program, meaning you don’t have to necessarily download anything to use it. To start drawing, hover over the art section at the top-right of ChickenSmoothie’s page. Select the “Oekaki Boards” option; this will give you an index of all the forums in which you can draw and sumbit your drawings. If you’re just starting out, and wish to develop your skills, I recommend starting out in
Beginner’s Oekaki. At the top right of Beginners Oekaki, you’ll see an option to “create a new drawing”.
If you have any specific problem, then I recommend browsing through the
Oekaki/Java Problem and Solution Thread to see if your issue has been previously addressed and dealt with. If you can’t find answers there, then try posting your own question. :)