Setting your goals in pronunciation is very important, especially when your time is limited. Nevertheless, your goals must be realistic and within your capacity as a learner.
Remember that English pronunciation is a skill that needs constant practice. The strategy that you use is not the same as when you memorize words because many parts of the body work together in order for you to make a single sound. Understanding the use of speech organs and how fast and well you can emulate your sound coach or pronunciation teacher as well as knowing your full capacity as a leaner will help you set your goals.
But, whatever goals you set and however long it may take to achieve them, they should all lead you to producing sounds intuitively. The result should be like a form of addiction in which you won’t be able to quit no matter what you do.