You can spend the night at Los Angeles International Airport. Security won't care about you. Any pier will do, as long as you go through the customs. If it is a joint journey, after the luggage is delivered, it will leave the security area of the international terminal. In the public area, you can take a free bus ferry to the next terminal, or you can go through the security check and enter the waiting area, where there are more chairs. There is free WiFi, but advertisements often pop up. There are many charging points. At present, most chairs have armrests, so we should sit and see if we can find a row chair without armrests, or find a corner to lie on the carpeted floor. Quite difficult. You can bring more clothes mats. Prepare some food. Because the restaurant is closed. Prepare a water cup/bottle, and there are water dispensers (not hot) outside toilets all over the airport. Tap water in America can be drunk directly. There are often cleaners working everywhere. They won't talk to you. It's just a little noisy At 4 o'clock in the morning, staff and passengers began to come and go at the airport. Don't worry about safety.