The best way to train yourself is "training", so you can learn all questions beginning with the easy ones, working up to the difficult ones. You can stop and start again at any time.
You want to learn more?
Selecting "More trainings" you can look at all questions concerning question catalogue topics, textbook chapters, teaching units or basic and additional knowledge. Or just learn only questions, that you answered wrong till now.
You can also use the search function (magnifying glass) to search for specific questions on a keyword, note them down and then learn about them in further training sessions.