Regarding fishing from the shore, you'll certainly do better in a boat, but you can also score from the beach. Almost nobody fishes from the beach on AC, but then almost nobody fishes, period, out of AC. There are limited places to fish from the beach, but if you're willing to get in a golf cart and get away from the resorts, bonefish and all of the local reef fish are in abundant supply. Ultra-light tackle with small spinners and grubs will catch almost everything. Rattletraps will also catch most of the reef fish, plus barracuda. Bring your gear, and Good Fishing. That said, ALL of the local guides can put you on fish for a VERY reasonable price.
I've done well catching bonefish right on the beach right near the rio. During the sunrise of the day i flyfish hitting the areas on the flats bare of turtle grass. Small shrimp imitations, and crazy charlies work out well. Then during the night when the tide is in, many of the reef fish come into near the beach searching for food sources. Light spinning gear and natural bait is more efficient than flies then lures in the darkness. Conch and sardines are deadly. The mula conch or horse conch is wonderful bait, it is smelly and it is tough and hard to get picked off the hook. The wind side of AC is really shallow and you can wade for hundreds of feet up to your waist if you are not really short. The leeside of the caye is filled with mangroves and with a mucky bottom. Basically, the windside is open for wading, but watch out for fast pangas, or fishing skiffs. I use wading shoes, not bare feet due to sea urchins and sharp objects. waders and fly vests are too hot for this climate, i use a fanny-pack stuffed with my gear, and of course a nail clipper on a retractor and a hemastat. Look for the areas without turtle grass, and try the muellas, or the piers. A good guide and a comfortable boat is a pleasure.
You can fish for bonefish from the flats at the cut just north of San Pedro, from the beaches north of the cut and from the docks and beaches in toen and south of town. Caught bonefish just about anytime water conditions were right, any time of day...Water must be calm.