White fish is easy to start for fish cooking but if you are budget hunter, sardine is the way . I go to local Farmer’s Market and look for super fresh sardine. One time I had four (4) good size ones only $2.0 or so.
It should have real CLEAR eyes without any redness. I call them “Happy Sardine” (as they never cried.) The rule of fish buying is that you should look for really bright and shinny ones as you may see them in live. If you have Japanese or Chinese friend, ask them for good store they buy fish.

The other thing you want to do before cooking fish is to make sure your knife is really sharp for cutting and cleaning.

You can cook them with good sea salt and broil like Japanese or Turkish people cook after you clean them; or marinade into the mixture of garlic (tons of sliced or minced), parsley, thyme, oregano, rosemary (if you like it), salt and pepper for over 2 hrs. Broil/ BBQ for Italian dinner.

Sea food supplies rare minerals like sea vegetable (Wakame, Nori etc.) does. Japanese gets good amount of iodine through sea vegetable from little bits from their daily food. Remember variation and moderation is the key for both fish/shellfish and sea vegetables.