Well, I didn't understand your question at first. I will assume that someone can become a UI/UX designer without prior knowledge of it. I would say that it is easy to understand all the basic terms through internet, books, and YouTube. But the main problem is becoming a professional in this field through basic knowledge. In my opinion, it is better to learn from experts who help us in providing all the required guidance to become a UI/UX designer. For that, I recommend you take up UI UX Course from a recognized institute like Intellipaat.
Do check out this UI/UX design training video for more information -