This does not have to be either/or, and Austin has already made some excellent points.
Some learning goes hand in hand. I remember that I saw an answer from you stating that for some clients you need to spend more time researching medical conditions or other circumstances. That is an example of two-for-one learning.
There is also upfront learning about the true business side of things. Incorporating your business and understanding all the regulations that you need to adhere to such as having liability insurance. I believe that it is important that you carry your business of fitness as professionally as you passion of fitness. But this is usually a one-time effort, and afterwards you only need to make sure that you stay current with changes to regulations.