Los Angeles is not one city you see, it's a dozen you drive between. It began as a Spanish pueblo in 1781, grew on oranges, oil and the railroad, and then film studios moved in because the light was good and the land was cheap. Today it's one of the biggest metropolitan areas in the country, with a coastline, mountains, a desert two hours east and very little that you can see from a single spot. The sights are real, the Hollywood Sign, the Getty, Venice Beach, but they sit far apart, and a bad plan means hours in a car looking at the back of someone else's.
That's why five days is the right length. Fewer, and you cross the city between breakfast and dinner just to tick things off. Five lets each day have one area: no zigzag, no second freeway of the day. The honest side: traffic is real (budget twice the time Google suggests at rush hour), the Metro is useful but not complete, the beaches are a pleasure mostly from late spring to early autumn, and Hollywood Boulevard itself is the most disappointing stretch of the trip. The food, on the other hand, is the best reason to come. Tacos from a truck, Korean barbecue, a French dip sandwich at a place open since 1908, Thai food that you'd be hard pressed to match outside Bangkok.
The plan: day one Hollywood and Griffith Observatory, day two Downtown (Union Station, Little Tokyo, the Broad, the Arts District), day three the Getty (the Villa while the Center is closed from March 2027), Beverly Hills and Miracle Mile, day four Malibu, Santa Monica and Venice on the coast, and day five a day trip to Pasadena and the Huntington. Start on a Tuesday: Griffith Observatory, the Getty Center and the Broad all close on Mondays, LACMA closes on Wednesdays, and the Huntington is shut on Tuesdays, so a Tuesday start keeps every door open on the day you need it. Heading further up the coast afterwards? Here's 5 days in San Francisco. More on the United States.