Your first quest is to make sure you have the right tools and equipment for this journey.
Answer questions on your knowledge of a topic. Succeed and you will move on to the advanced levels of mastery.
Or ... face a challenge, perhaps you will prove you are worthy. Any areas that need strengthening will be identified. Collect evidence of your new skill in a portfolio /blog.
Choose a skill
Start with leveling up your Twitter skills, or look what other learning communities are available.