First of all, go to www.php.net the official PHP website, then download, its manual, I will suppose that your operating system is MS Windows, in .CHM format.
Second, download PHP binaries for windows, keep in mind, to get the complete binary in .zip, not the installer.
Third, download the apache webserver 1.xx from www.apache.org
After that, Install apache, then read install.txt file in the folder inwhich you extracted the php zip file, to know how can you makes php works with apache.
This may take not more two days to get it.
Then one day to test some basic coding from the manual.
After that, go to www.mysql.com to get a copy of mysql database server, then install it.
From any website has tutorials for PHP you will be able to connect to the database.
Hard work and concentration you may able to do any thing you want with php in 3 weeks maximum.
Choose a good book is wise idea.
