I live in LA and want to spend a couple of days in a city I've never been to. Good public transport is big plus but I'll use Lyft if I have to. I like museums, libraries, public parks, historical sites, and I'm kind of a sports bro so I'd like to catch a baseball or soccer game. Probably take a week in April. So far I'm leaning towards NYC, Chicago, or New Orleans.
NYC is a must-visit for anyone imo. If you enjoy something, you'll find it in NYC. Plenty of diverse neighbourhoods so you can find whatever vibe you're after. I'd recommend against doing the whole Times Square / typical touristy things unless you love crowds and hate yourself. Brooklyn is more interesting for food and strolling imo, while Manhattan had most of the museums I visited.
Chicago I've only been to once but really enjoyed it - I haven't been to enough US cities to make any sensible comparisons but the transit was fine and there's plenty of museums and stuff there too.
If you're used to LA transit you'll find that both Chicago and NYC are far more hospitable to those who don't have cars
Can't speak for New Orleans, but it's definitely on my list of places I'm hoping to one day visit as well.
My thoughts probably don't count for much since I'm sure some locals will chime in, but ultimately as someone who visits the US once in a blue moon I'd say you can't go wrong in NYC
I have cousins in Australia who pretty much said the same thing about visiting NYC.