Being Spanish, I'm all about fish and seafood in general. Two of my favorite recipes are these:
1. I buy fish fillets (typically something like cod), tomatoes, and onions. I slice the veggies into thick slices and put them in a glass dish with a little olive oil and throw it in the oven at about 350* for like 15 minutes or so. Right until the veggies are soft. Then I throw in the fillets (I usually bury them in the veggies), with a bit of dill weed and salt on top, and let the fish cook for another 5 minutes.
I'm a big fan of onion and tomato together so I love this dish, personally. Alternatively, I will make fish fillets very lightly fried with just the tiniest drop of olive oil and lemon juice, and pair with whatever vegetable I want (usually cauliflower.) You can do anything with fish, really.
2. I love a shrimp and avocado "salad." For a few people I will take a pound of pre-cooked shrimp, chilled, two avocados, a small red onion, two limes, a small tomato, and salt and pepper to taste. I will mince the onion and and let it soak in the lime juice from the limes while I chop up everything else (it takes out the sting from raw onion.) Meanwhile I will peal and chop up the shrimp, tomatoes, and avocado and mix it in a bowl with a little olive oil, salt, and pepper. Then I'll dump in the onion with all the lime juice and mix.
Avocado is an excellent food, full of good oils and antioxidants (as well as the raw olive oil), and who doesn't love shrimp lol. Shrimp is naturally high in sodium though so watch the salt you add to the recipe if anyone in the family is on a salt diet.
And my only other tip is to sign up for a class that you really LIKE. Something ridiculously fun like bellydancing or Akido! Something that is an exercise but where you're having so much fun that you don't even realize that you're losing weight and toning up. It'll be much more easy to go to vs. the gym, you'll have fun, and you may even come out of it with a few friends and a new skill.