Congrats on wanting a cat!

You'll need to read up on what plants & food are poisonous to cats. I would hope you wouldn't declaw your cat, if you know nothing regarding declaw, please do some research as to what declawing truly is. Then you'll ned to learn how to train your kitty to use scratching posts instead of your couch

As for getting a kitten to ensure all the animals get along: that is somehwhat a myth. If you got a kitten, be prepared for it ot drive all the other animals nutty. Kittens are high energy and demand A LOT of attention. If you get a kitten, its usually recommended to get TWO, so they have each other to entertain instead of relying on meowmie and the other animals who don't necessarily have the same energy level. I always suggest an older kitten, about 6 months if you want a kitten... because by then its true personality is there. All kittens are cuddly, lap kitties. That goes away by 6 months. Then who's a lap kitty then will truly be a lap kitty. Who is independant then will be an independant kitty. Think about what kind of cat woud best fit into your family. Will you be happiest with a cat that is social and intereacts with you and the other animals? One who is into everything and always your shadow? One who is quiet and docile? One who would enjoy the company of the other animals, but prefer to be left alone? All these things should be really thought out before had, so that when you go to the shelter, you say what kind of cat you're looking for. Of course, there's always the chance that one will pick you... then you know its right!