Hello Rob, hope the lack of replies hasn't downheartened you! lol
I've actually never fished Ayr from the Shore, used to go out on the boat a good few years ago though - never seemed to catch that much.
I'm not the best one to give advice, but it'll tell you what I use, and then maybe others will add their bit.
I used to fish Largs (black rocks) up to Port Glasgow (with varying results).
A 12ft Beachcaster, large fixed spool reel (or Mulitplier) 15-18lb line, 50lb shock leader (general rule 10lb per 1oz of lead weight)
A simple rig with single 2/0 or 3/0 aberdeen hooks, 18in hook length (12-15lb on sandy bottom or 18lb + over rough ground)
If you can get peeler crab, then you should get better results, although Lugworn, Ragworm and mackerel baits all work well depending on what you're fishing for.
for example, fishing Crab, might get you a Cod, whereas rag / lug might get you a flounder.
I'm only going on my own experience here, so other Anglers will probably have other advice.
I've learned by trial and error (lots of errors! lol), and I usually always stop for a chat with other Anglers, just incase I pick up that one piece of Killer info.
Buy a Sea Angling mag, they can be really helpful, or have a chat with your local tackle dealer - most will not try to rip you off if they know you'll come back.
All the best, and make sure you let me know if you catch anything.
Cheers!
Col