Imaging if you are a student and have to write an essay for university.
The smart way to first start is to construct your writing plan. Then you know exactly where to look for information when you start reading books in the library. If you just start reading books without first knowing exactly what you are researching you will waste a lot of time and also be overwhelmed by the available information.
The same logic can be applied to trading. If you have an idea of what trading strategies you might use, it is a lot easier to identify useful tools.