What are you going to do after saving data to a PHP file? Do you want to upload that file to server? And what?
I think that is not the right approach if you really want to save any kind of data to server (online). You can do one thing. Write a web service which you will be consumed in your android application. You can upload data and images to server.
For uploading large sized images use a better compressing techniques to avoid more bandwidth.
A google dev site tells -
http://developer.android.com/training/basics/data-storage/databases.html[
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As you said you are new to programming, this might be a little complicated. But if you love to do it, you can do it. Its not a magic, its a program.
Regards,
Ganesh