"Free will" is merely a word and words are made by us and not some superior being so how can we understand it.
All of us have different interpretations of "free will".
Does free will differentiate us from animals?
First learn php. That is a good start.
If you plan to develop offline use something like easyphp to make a offline server so that you can test your code and look for some tutorials
When you use Microsofts calculator's Exp function it does not raise the number you enter exponenently it requestions another number and then does this
result = firstnumber * 10^second number
What is it doing?