Hi Geoff,
[I'm a version or two behind with Adobe at the moment and pretty rusty as well, but this should be ok...]
When ACR opens you should see a field called "Profile" near the top of the right-side panel - it will probably have a default something like "Adobe Color". Just to the right of this is the "Browse Profiles" icon (3 rectangles and a magnifying glass) - click this to open the panel.
There should be an entry called "Camera Matching" - clicking this should open a selection of profiles that are available for your camera model. Just select the one you want. (Note that these are Adobe's interpretation of the profiles so may vary a bit from the camera).
If you want to pick up the profile from the camera automatically do this:
From the main PS menu select Edit / Preferences / Camera Raw...
This will open a dialog box. In the left-hand panel click on "Raw Defaults". The panel for this will show a field called "Global:" which will likely be set to "Adobe Default". Click this dropdown and select "Camera Settings". Then click "OK". When you open a raw file from then on, Adobe should read the camera settings from the file.
Additional note - if you have some 'standard' settings that you usually apply to most images (e.g. sharpening, noise reduction, etc) you might want to look at creating a preset. (A preset can be set up to run automatically when a file is loaded). Should be plenty of You Tube stuff on how to do this if interested.
Hope this helps...
Cheers.
- Phil.