Firstly, you need to turn your iPhone 7, I phone 7 plus or IPad, there will be hello in many languages simple press home unlocks here and see your device start up.
Select your language and your country also this step is important as your device will display what to show on screen including contacts dates and more.
Then to activate phone you should connect it to network weather it is Wi-Fi or a cellular network but before all this you should insert sim card in your brand new cell phone.
Now Set up touch ID with this ID you can make purchases and It unlocks your phone. Six Digit pin code is next thing to create and this will protect your phone. If you have iCloud, then you can transfer your data from old devices to the new I Phone.
Now Sign in with your Apple ID .and if you don’t have one then tap Don’t have an Apple ID. Now you can create your Apple ID from here and accept iOS terms and conditions here, you can also set up Siri which can recognize your voice and answers your questions.
Whether you have an iPhone 7 or iPhone 7 Plus you can customize your home screen by the applications you use most frequently.
Always remember to back up your data of old phone to I cloud because only back upped data will only be available on your new I phone.
In new phone you just need an Apple ID to transfer data of Old phone to new One. Text messages are not included in this but there are many applications that can do this task too.