Depending on the weather the reds can be in those shallow ponds or stacked in a hole if a cold front goes through.
Current is key if you are just starting out. Look for moving water and you will find reds, sea trout, lady fish and others.
If you are dead set of fly fishing for them, then you will need a way to get elevated in your boat, even if it is only a few feet. Fish the shallow ponds with clear water so you can sight cast to them. Often the ponds with stained water will be better but you have to find tailing fish or actively feeding fish or you will be worn out before you find the fish. A big noisy popper can bring exciting strikes.
Here are our top baits.
1. Jig under a popping cork
2. Weedless spoon with curly tail trailer if super shallow/weedy, no trailer if water is less weedy.
3. Snagless sally
4. Wobble rite gold spoon. (various sizes depending on current, depth, and wind.)
5. Baby -1. Pulled just under the surface so it pushes a wake.
Its easy to get lost in the marsh so bring a GPS, maps are a huge help. There is great fishing within a few minutes of the boat ramp so don't feel that you need to run far.
If the weather is bad, half a cracked crab fished at the edge of the channel or better yet, where channels meet is a killer bait for reds, big reds in particular.