The specified time refers to the year of your exam results and the next two years, so if you don't have enough time to prepare for the exam, you can choose to apply for a single subject.
As for learning, it is suggested to start with the basic knowledge of futures, which is more difficult and has more calculation problems.
However, if you have a good memory and have no time to prepare for the exam, you can start with futures laws and regulations. Knowledge of futures laws and regulations mainly depends on memory. Generally speaking, you should study hard and learn most of the relevant knowledge of the futures exam outline, so that the exam will be easier.
Which subject to test first, you can choose according to your own situation!