where is home on iPhone screen

You can skip setting up Touch ID, and not set a passcode if required.

For Touch ID tap on the "Set Up Touch ID Later" option in blue.

For the Passcode, tap on "Passcode Options" and select "No Passcode".

Get started with iPhone, iPad, and iPod touch - Apple Support

With that said it is strongly suggested to at least have a passcode set to prevent unauthorized entry to the iPhone if you ever lose it or it is stolen.

You can turn off icloud in Settings, by signing out. It should not bother you again unless you attempt to do something that requires iCloud.

With that said, its not about being able to buy a new iPhone, but about not letting just anyone who finds your iPhone have access to your files and content. Or are you okay with letting just anyone be able to buy stuff form the itunes or app stores and charge it to you, or look at your e-mail or messages and be able to message anybody in your contact list?

Home is the home button at the bottom of the phone.

That would be the round button / touch id sensor also know as the "Home" button.