Outside of your house!
I guess that question implies that you’re new to LA. Actually, even if you aren’t, it can be hard to meet people in Los Angeles. It’s spread out for miles and is a huge collection of neighborhoods. It’s a very much a car town. I think that’s why our comedy scene is bigger than New York’s and Chicago’s. It’s a way of connecting.
I urge actors to also join the union when they can. That gives you eligibility into SAG-AFTRA events, SAG Foundation events, and the Conservatory as well. At the Conservatory you can sign up for multiple classes for a minimal fee. You have to check the website to learn what the current fee is. Once you become a union member there are events all year long. Attending those events will give you the opportunity to meet people who are doing what you’re doing.
A lot of actors think of joining as an obstacle, but it’s not. It helps in many ways, the least of which is building community.
Of course, go to class and STAY in class. But step one? Get out of the house!