What does Pip learn about being a gentleman?

Pip is a poor orphan boy who knows nothing about the real world and certainly nothing about the world of the upper class. Miss Havisham is the second person of a higher class that he meets in his life, and her adopted daughter Estella is the first. Because of her beauty and superficial sophistication, the haughty girl becomes a symbol of everything desirable in the world--but Pip fails to realize that when he meets the haggard, forlorn Miss Havisham a few minutes later, he is also seeing what Estella will be like in the future.
By a miracle Pip finds himself chosen to become transformed from a blacksmith's apprentice into a real London gentleman. He does not realize that being a gentleman is not a real occupation. In fact, most gentlemen are incapable of work and despise work. They treat honest working men with contempt--an attitude which is a sure mark of a gentleman.
A good example of gentlemen is seen in Chapter 34 of Great Expectations, where Pip describes the behavior of the young members of the "club" called "The Finches of the Grove."
So now, as an infallible way of making little ease great ease, I began to contract a quantity of debt. I could hardly begin but Herbert must begin too, so he soon followed. At Startop's suggestion, we put ourselves down for election into a club called the Finches of the Grove: the object of which institution I have never divined, if it were not that the members should dine expensively once a fortnight, to quarrel among themselves as much as possible after dinner, and to cause six waiters to get drunk on the stairs. I know that these gratifying social ends were so invariably accomplished, that Herbert and I understood nothing else to be referred to in the first standing toast of the society: which ran, “Gentlemen, may the present promotion of good feeling ever reign predominant among the Finches of the Grove.”
These unfortunate gentlemen have nothing to do with their lives but fill up the time from morning to night. Pip has a big advantage over them because he has grown up in a household where a man works hard to produce things of value to society. It is appropriate that Pip's first role model was a blacksmith, doing the hardest kind of work. Pip's friend Herbert has a sort of negative advantage in seeing how his father Matthew's fecklessness has led him into a desperate situation. Herbert is a gentleman, but he knows that being a gentleman is not really an occupation. He wants a real occupation. In the end, Pip comes to respect people who work for their livings and are an asset to society rather than a burden and a bad example. Pip realizes that he should have made something of himself, something other than a "gentleman." A real gentleman does not allow himself to become a helpless dependent and a parasite.
By the beginning of Chapter 34, Pip realizes he is on a slippery slope.
When I woke up in the night—like Camilla—I used to think, with a weariness on my spirits, that I should have been happier and better if I had never seen Miss Havisham's face, and had risen to manhood content to be partners with Joe in the honest old forge.
Pip's greatest insight comes in Chapter 39 with the shocking appearance of Abel Magwitch out of the howling storm of reality, who reveals himself as Pip's secret benefactor. Pip realizes with horror that he has been made into a weak, improvident parasite and has satisfied Magwitch's idea and ideal of a "gentleman"--a loafer, a man-about-town, a clothes horse, a spendthrift.
Yes, Pip, dear boy, I've made a gentleman on you! It's me wot has done it! I swore that time, sure as ever I earned a guinea, that guinea should go to you. I swore arterwards, sure as ever I spec'lated and got rich, you should get rich. I lived rough, that you should live smooth; I worked hard that you should be above work. What odds, dear boy? Do I tell it fur you to feel a obligation? Not a bit. I tell it, fur you to know as that there hunted dunghill dog wot you kep life in, got his head so high that he could make a gentleman—and, Pip, you're him!