Familiar reading means reading aloud skillfully and fluently, which generally does not include understanding. Because like classical Chinese or English (which is difficult for you), just because you can read it fluently does not mean that you fully understand its meaning, grammar and main content. As long as you read it aloud correctly many times, you can generally read it familiarly, but it is also important to master some skills.
Personally, I think the method of "understand first and then read thoroughly" is better. For example, in classical Chinese, if you know the meaning of the words and sentences, you can read them aloud more smoothly. The same is true for English. And this method can also be recited quickly.
The "three-time reading method" summarizes some methods:
Read three times, read it quickly the first time, and read the content roughly before doing the next time. Read a masterpiece to get an initial impression, then appreciate the beauty of the work, and finally read it intensively. As he said: "You should read a masterpiece at least three times. It is best to finish it quickly the first time. It is like a bird's-eye view on an airplane. Panorama of Guilin.
The second time you need to read it slowly, chew it carefully, and pay attention to the structure of each chapter and paragraph; the third time you need to read it carefully, paragraph by paragraph, to understand and apply it. At this time, we should pay attention to its concise words and sentences. "This reading method can help us extract the essence of the book.