NYC is a lot more visitor-friendly than LA is, but getting good local advice on LA is priceless, so good on you for asking. I've lived in LA for 14 years but have a place in Central NY near where I'm from so don't let my NY location fool you!
General advice:
-Things look closer on a map than they actually are.
-Do your traveling in sections/areas/regions or you will be stuck in traffic and be miserable.
-Understand that there WILL be some traffic up to double the time without traffic- put on some tunes or a podcast and roll with it like the locals!
-Use the Google Map feature where you can enter your departure or intended arrival time - the time-range estimate might say 35-55 mins and that's because for the time of the day you are looking at, traffic can make the route up to 55 mins. Plan for the 55 mins and you won't be late, you might be early, or when you check traffic when you plan to leave, you might decide to wait another 10 mins if things look clear.
-My favorite area of LA beach is exactly where the Palisades fire was and was absolutely devastated in January. Be prepared that if you are around the beach area north of Santa Monica, it can be pretty heartbreaking, and also the environment is pretty toxic still so I'd avoid north of Santa Monica with windows open, personally.
-Seeing the touristy things can be fun, but I'd plan them as part of a bigger day, a stop en route, rather than a thing in itself (definitely walk down Hollywood Blvd - see the stars, the theaters, the colorful performers, etc. but I wouldn't spend more than an hour around there).
-Know that LA is it's own thing and is not like other cities - best to embrace what it is rather than what other cities have that it doesn't and you won't be disappointed.
Places I take my out of town friends:
-Griffith Observatory (in a park) or Wilson Observatory (in the San Gabriel Mountains).
-A hike in the San Gabriel Mountains, which will blow up every LA stereotype there is.
-A shorter hike with views (Elysian Park, Ascot Hills Park, Ernest Debs Park, Santa Monica Mountains for ocean views - but not now because they were part of the fires, etc.)
-The Getty: it's a great museum, but equally fantastic grounds and views!
-DTLA: Grand Central Market, Bradbury Building, Cathedral of the Angels, Last Bookstore, Los Angeles Public Library
-Little Tokyo + Union Station and Olvera Street area
-Barnsdell Park is a great spot for a picnic/take out lunch if you've been hanging out in NELA (Los Feliz, Silver Lake, Echo Park)
-A Taco Crawl (research and put one together or do a organized one: https://latacocrawl.net/)
-Tide pools in Palos Verdes (usually paired with Wayfairer's Chapel, which is currently closed due to land shifts). Kayaking near Naples in Long Beach and strolling 2nd street (Belmont Shore). From where I live, I'll stop by Watts Tower on the way for either of those things.
-Unfortunately, the Lake Shrine Gardens where I usually take visitors were damaged in the fires and are closed. Descano and Huntington are also great!
Misc:
I highly recommend these walking tours, they are super informative and I've enjoyed them as a local! - https://www.laconservancy.org/tours-events/walking-tours/.
LA has lots of great museums! La Brea Tar Pits is unique, Broad and MOCA are close to each other and free in DTLA, Rose Gardens plus expo Park museums make a nice day.
If you can find a show at the Hollywood Bowl, it's like little else (The Greek is also great!).
LA has lots of great theater, and you can often catch a more famous actor in a play here on their off time. Pasadena Playhouse, The Geffen (UCLA, and go to the Hammer Museum while you're there!), Ahmanson and Mark Taper, East West Theater, plus smaller spots like The Fountain, Sacred Fools, Atwater Village Theater (have dinner at Momed).
