How can I download and install Apply TV on my iPhone 4s? Also please help me to transfer files from my old phone to iPhone 4s. My old phone is not a iPhone.
If you meant Apple TV then there is no "Apple TV" for the iPhone.
Also you don't have to install anything to use your Apple TV with your iPhone.
This is done via AirPlay.
For your other question I suggest you start a new topic and also state what your old phone make and model was as there are various options depending on the phone, where and how the data is stored etc.
which old phone you have?