If you want to make your cat happy, just give it everything it asks for. Start with plenty of food, water, and litter boxes. Then make sure your cat feels safe, so give your cat plenty of hiding places away from people, dogs, and other cats.
Next, make sure you provide plenty of stimulation for your cat. That means hunting toys that allow your cat to stalk and attack something, preferably not you. Some people think cats are easier to care for than dogs, but that’s probably because they never tried owning a cat.