You sir are experiencing a VERY common dilemma. One thing I would suggest is to pick up some of the local fishing hand outs. Most have a section about what fish others are catching offshore. This indicates what fish a seasonally moving through the area. Watch for King Mackerel. Those are a good starter, since they are plentiful and easy to catch. Trolling, or even casting larger spoons and plugs. Many buy, and troll rigged Ballyhoo. These fish travel only a 1/2 mile or so offshore.
There is an old very true saying : " 90% of the fish are in 10% of the water ".
For other fish you need to find the reefs and wrecks in your area. The county has a listing of all the man made ones if you look online or pick up a copy at a county facility, or even the big discount store may have them on the counter free. Most of the water you are fishing is like a desert. Nothing to eat, and no cover. Just a sandy bottom.
You bait choice is not good either. You would use shrimp where shrimp are present. That is where fish are thick feeding on shrimp. A shrimp by itself in the water will NOT attract fish. So, try this, There is a thing called a " Sabiki Rig ". A multi hook affair, with what looks like a bunch of fishing flies tied to it. Buy a couple packs of those. Main thing there is that there are two basic types. One has artificial " wings " on the flies, and the best has real fish scales used. Buy only the real fish scale ones. Then you need if you do not have a couple a one ounce pyramid sinker. At the end of the Sabiki rig there is a snap swivel, put that big sinker on the bottom of the rig. Now you can catch live bait for yourself, and are no so helpless. When you head out stop periodically and drop the Sabiki over the side. Especially if you see diving birds near, run there and your set. If you do not start catching bait immediately run a little further till you find the spot. Just throw a couple in your live well. That Sabiki will keep you set with all the bait you need. Live baitfish. Now your fishing. Free line those off the boat, as many rods as you can tend.
You will only catch the fish that are available. You have to find the 10% of the water the fish are in. And watch your tides. No tide = have a sandwich take a nap or whatever cause it will be near a waste of time fishing. And now sir, you are not so helpless, you have real live baitfish and have at least some idea of what your looking for. Now all it takes is about $1000.00 in fuel to learn as we all have burned through ourselves. And that is why most are not real quick to help.