There was a previous film about this family -"A Family Affair" - made also in 1937. That starred Lionel Barrymore as Judge Hardy and Spring Byington as Mrs. Hardy. Also the Hardy's daughter is married, and her marital problems figure into the plot in a major way. Mickey Rooney is very much a supporting character at that point.
This film changes everything. Lionel Barrymore had health and mobility problems, so Lewis Stone takes over the role of Judge Hardy and very much makes it his own. Spring Byington was not under contract to MGM, so she is not in this film or any other Hardy pictures as Mrs. Hardy. The rest of the supporting cast remains the same, except now Judge Hardy's daughter Marion is now magically single, never married, because more interesting situations can come about that way.
This film takes the family to Catalina Island for a vacation - a long way from Carville. No one family member takes center stage. Instead, both Marion and Andy have romantic problems and learn a few lessons. Lewis Stone as Judge Hardy is probably the central figure if anybody is. And Judge Hardy, before leaving for vacation, takes a chance that could leave the family bankrupt if things don't go his way. And he never even bothered to talk to his wife about it UNTIL it becomes a problem!
MGM apparently correctly judged they had a winning formula in the Hardys, since Lewis Stone appears in a rare epilogue to talk about how this will be a series. It turned out that the series is a good representative of MGM's output prewar and probably American values and outlooks pre war as well. WWII changed everything, and though the series had installments after WWII, it was never quite the same.
This is a good introduction to the Hardy family as it existed in every film but the first one. And that first one is worth watching on its own terms.