I was updating my iphone 4s to IOS 9.0.2 and my phone displays it was updated successfully. There are just a few more steps to follow,and then your done.. However It kept on prompting onthe icloud set up page and on the find my iphone pag

Will It not let you continue past the find my iphone page? I had to do these steps also when I updated my ipad but I was able to set mine up.

If you can not continue past those pages you can maybe try plugging it in to your computer and reloading everything from itunes. If you have never synced it with a computer with itunes then you will have to take to the store unless someone else has a solution. Were you able to set up your icloud? If so just make sure you are using your original icloud account information. Good luck and I will be on the look out for any solutions for you.