Really scenic spot with not many amenities at it. On a good day, you can see clearly out to the Paps of Jura, and even Fairhead over in Northern Ireland.
Westport is technically a part of the same beach as Machrihanish, but typically they get referred as two distinct locations. I think that's purely down to how the waves break here - where this entire bay could be seen as a sliding scale; Westport, being the more punchy location, while Machrihanish is typically more mellow. Somewhere in the middle is the appropriately named "Middle Beach" lineup, which kind of gets a mix of the two.
For food and other amenities, heading into Campbeltown is probably your best bet.
Pete's Surf School also operates a trailer for rentals during the summer, but can be contacted during winter months to have boards and wet suits dropped off.
Seems it works best on a mid to high tide, as it tends to just close out and crumble on lower ones.