Staying in the US for 6 months

I just have a simple question, I am planning on taking an extended vacation to the US for the allowed 6 months as a Canadian citizen. I will be driving to California, for some much needed vacation time and staying with a friend of mine who is a US citizen and has a home in California. I will be retaining my residence in Canada and have zero plans of working (I know its forbidden lol). I was wondering at border control do I simply state that I am planning on staying in the US for the maximum allowable time? I of course will provide my friends current address and my address in Canada, but is there any other pertinent information I would need to provide.

Any help would be lovely

You may need to show proof of your Cdn residence, lease/utilituies/etc.