What kind of pet would you recommend for me?

Hi, I'm a 15 year old high school student. I want to get an exotic pet, but am not sure which one is right for me. I have done some searching and have found a few animals that caught my eye. Some of the animals that I saw were the African Pygmy Hedgehog and Red Eared Slider Turtle. I was wondering if either of those animals would be right for me, or if you have have any other suggestions for a pet. I have a fair amount of time to take care of a pet, but not a massive amount. I also have a fairly large backyard, but much of it is paved over with cement and water features, so it isn't great for large animals that like to run around a lot. I would prefer an animal that lives primarily inside. By the way, I should also mention that I live in Washington State, because I know that for some exotic animals there are legal issues you have to be aware of. I also have a 5 year old sister, so a pet that is good with young children would be important.