This step is important, because it allows you to interact with someone in your chosen field or fields. You can ask questions and get a dialogue going.  Talk to the mechanics at the garage you take your car to, get the person who is fixing your computer to give you an overview of what they are doing to fix it. Prepare questions in advance and during a lecture or class at a college, community center, or museum. If they haven't been answered, afterwards approach the speaker and ask them. Speakers almost always are happy to engage further in their chosen material. Be polite and respectful. Museums often have a contact number or email. Approach them with your questions. It might take them some time to reply and they might not know the answers, but they can often put you in contact with someone who does. Professors usually have a university email somewhere on their university's website. You could try sending them an email outlining your interest in your subject and asking for their help. Remember that professors are busy people, so don't contact them around midterms or finals. There are certain internet resources where it is possible to talk with an expert and ask them questions covering a wide variety of topics. Gathering knowledge, learning, is a lifelong endeavor. Pay attention to the world around you to look for new opportunities to learn. Keep an open mind and learn from your mistakes and you will be quite knowledgeable. Information changes constantly, be it science, literature, or even wood working. Keep learning on your chosen topics.

How would you rephrase that briefly using Vietnamese?
Nói chuyện với chuyên gia. Thường xuyên theo đuổi kiến thức.