Well, php is used as server side language, so i would (if you haven't already) do the html + css course, so you can build a front end. Then learn sql, so you know the basics of a database, then learn sql + php, so you can also store things in a database with php.
Then you might want to read a bit about hosting, find a shared host (many shared hosts support php), and you can build your website + database. Do read a little bit about security as well
If you don't want it on a public hosting, you can also install xampp for windows, it will give you mysql + php + location for your html + css files, and you can experiment with it.
Maybe i should have recommended xampp in the first place
Anyway, hope this helps