What I would do is cut fish into portions over the weekend and make something simple when you get home, like salmon teriyaki or trout in almonds (you might want to chop the nuts over the weekend). If you froze your pre-portioned fish, put it in the fridge the night before you plan to cook it to defrost.
Step 1: Bonk and bleed out the fish. In order to minimize suffering for the fish and prevent spoilage of the meat, fish must be "bonked" and bled out immediately after removing the hook. Step 2: Remove scales or skin. Step 3: Open the belly and remove the innards. Step 4: Prepare for cooking. Step 5: Cook the fish.