How do I get there by bus from my century city?
There is a trip planning tool on metro's website that you can put in your location and then the Natural History Museum. I can't put the url in this response, but you can just google Los Angeles Metro and it will come up. This will give you the different bus routes you can take. Alternatively if you find a bus to Culver City, you can catch the Expo Line that drops off right in front of the Museum.
Get quick answers from Natural History Museum of Los Angeles County staff and past visitors.