[Rookie Redfish]

Not so good.
Caught 1 trout a few drum and about 30 Croaker.
Met a guy who told me to try a orange floater and put a gulp shrimp on it. Chartuse??
I dont know what i'm doing wrong, cant seem to catch like the rest of the guys out there.
I fished fresh water all my life and can catch brem and sac a lait all day long. But this salt water is throwing me for a loop.
I tried different hook sizes and stuff. Still cant get the big reds, trout or flounder.
Guidance needed... Thanks everyone.