Chinese or Malaysian language (Kuala Lumpur)

Hi everybody,
Currently I am in a discussion with my company to move to KL for a while. Before, I want to start the very basics of the language which is used there. As far as I read, some people speak Indian and much more Chinese and Malaysian. Is this right?
For work, I will speak English, but when I got out to somewhere else, I prefer to speak also a little bit the local language. My question is: do most people speak English there (also on markets etc.) and should I start learning to speak Chinese or Malaysian?
Thank you