You've already turned yourself into a kid, and it would be a shame to waste a spell. So, you decide that you might as well an enjoy yourself for a little bit.
So, you decide to spend the day enjoying things you used to do as a kid. You think for a moment, trying to decide what to do, then head to the kitchen. Along the way, you once more struggle to keep your adult clothes from falling off, then stop and think for a moment. No one else is here, and you're just a kid, so you don't know any better. You let your adult clothes drop off you, and continue to the kitchen naked, making it much easier to walk without tripping.
Once in the kitchen, you stop to think once more. Normally, at this age, you would have a parent around to aid you with this task. However, you have long since moved out from your parents' house and into your own apartment. Well, it shouldn't be to hard. You move a chair over to the side of the cabinet, and climb up onto the chair so you can reach inside. From the cabinet you get a bowl, then climb down the chair, and retrieve a spoon. Then, you search your closet for cereal, and the fridge for milk, before heading to the living room with these objects. You then make yourself a bowl of cereal, turn on the TV, and begin to watch cartoons.
A couple of hours pass, and Spongebob and his friends become a bit boring. So, you try to think of something else to do. Then, you remember when you were a lot younger once, you took all the pillows and bedsheets in the house, and made a fort in the living room. Well, that should still be fun. So you gather up your bedsheets, and a few pillows, and make as good of a secret fort as you can.
You also make a mental note to take it down when you change back to your adult self later. That may be a bit difficult to explain if you have guests over.
You hide in side the fort, and try to think of a game to play, and then realize you don't have anyone to play with. You feel a bit lonely. Maybe you could go outside and play and meet someone? No, you can't do that. You don't have any clothes this size to go outside in. Maybe you should just change back to an adult now. Then again, you're also feeling a bit tired. You could just take a nap.