Learning language is like learning how to ride a bike. At first, you don't know how to ride a bike, and you may not even know what a bike is. Just like you don't know any words in a language when you are born.
As you grow up, you start observing people around you and start making sounds. Similarly, you start watching people ride a bike, and you may try to imitate them. People around you help you by correcting your mistakes and encouraging you to keep trying.
In the same way, as you grow up, people around you will teach you words, correct your mistakes, and encourage you to keep trying until you start making sense. You also learn the structure and grammar of the language as you continue to listen to others speak and read books or watch videos.
Over time, you master the skill of riding a bike, and it becomes second nature. Similarly, with time and practice, you acquire language and become fluent in speaking, reading, and writing in that language. The more you practice, the better you become, just like when you practice riding a bike.