It depends on the context. Since the past perfect is used when discussing two or more actions/conditions in the past, it is often used to “set the stage” or provide background information for what is next described. It is very common in newspaper articles when describing ongoing stories. For example, in today’s New York Times the first article I looked at included the following sentence, “On Friday, the president sent a letter to Congress that was an unsubtle rebuff to Democratic leaders with whom he had previously met on Wednesday.”
Another random sentence from a non-fiction book: “Berthe and Simon were bilingual…France was their home; neither had known any other.”
The verb form is also used in fiction but I would guess it is more common in literature that contains rich descriptions than in popular action thrillers and novels with a lot of short dialogue.
Keep in mind that it is possible to make the sequence of past events clear without using the past perfect tense if one includes other words.
For example, compare the following two paragraphs which describe more or less the same thing. #1 is written without the past perfect., #2 uses it.
(1) When I knew John in college, he was on the running team. After he graduated, he put on weight when he got a full-time job with long work hours. He then switched jobs, met a woman who was very active in sports and started running again.
(2) I had known John in college when he was active in sports. Once he graduated and worked full-time, he no longer was training and thus put on weight… However, by the time I saw him again four years later, he had switched jobs, met a woman who was very athletic and had himself taken up running again.
In informal speech, young children do not use the past perfect tense and I suspect that it is not common among teenagers although frankly I haven’t spent a lot of time listening to the latter lately. It is used among adults but it would depend what they are discussing and its complexity.
Another common usage of the past perfect tense (in speech as well as in writing) is in conditional sentences.
If you had helped me, I could have cleaned up faster. If he had done the practice exercises, he would have done better on the exam. If it hadn’t rained, we could have gone hiking.
For a learner of English, I would recommend learning what the tense means so you recognize it when you read it or hear it. However, you can probably avoid having to use it unless you’ve read/heard a lot of examples.