Can I build Android and Chrome for my phone?

This is an experiment to determine whether or not Android (and Chrome) are really open source. And, since I'm not much of a systems programmer it will give me a tour of my machine's capabilities in that regard. I'm comfy at the command line and am fluent in both Linux and OSX. My phone happens to me a Moto G, if that matters. (I also have access to a Galaxy S7 and Nexus 6P). Thanks!