I know this is supposed to be easy, but I can't seem to figure out how to use GA for my site. Is it something I do inside my ACP, in my Google account, or both?
And is digitalpoints add on something to be used in addition to GA or in lieu of it?
Most likely, that's the correct ID number. Try it out. Note that it can take a long time for data to start showing up in GA, so give it lots of time. 6 hours to be safe.