There are many primers on how to start with Ursula K. Le Guin, all of them perfectly fine, but I haven’t seen any that just go with “Start with what’s available and easily accessible”.
“The Ones Who Walk Away From Omelas” is available online, and it’s only four typewritten pages. Confession: I hadn’t read this until today. You may think, as I did, because you know the story through osmosis (as probably many people who are familiar with sci-fi do) you don’t need to read it. You would be wrong.
This website has collated stories that are available online. They all appear to be from free sources like Baen, Lightspeed, and Clarkesworld.
She blogged pretty extensively for many years, and there’s some lovely stuff in there. Her penultimate entry was about her cat Pard and the Time Machine. (just Ctrl + F for “pard” on the archive index. Trust me.)
Don’t let me stop you from going to the library or your online bookstore of choice to get her books, of course, but there’s plenty of stuff available that you don’t have to go very far to access.