heya nice to have you,
firstly your right PHP has to be installed on a server its what's know as a Server Side Language, thus unlike HTML which is proccessed by
your computer PHP is proccessed by the server at the other end. Most web hosts have PHP included if you get a slightly premimum package, however sites like Yola tend not to because potentially as it is proccessed by the server if they start letting you loose with PHP you could screw around with their servers

.
What i sudgest to you personally is you have a look at a hosting site named Heart Internet its been a while since i used them but i remeber they offered good value for money start up packages. I then sudgest you start looking in to your own website, it may sound daunting but don't worry there's loads of free website templates with a free editor such as Coffee Cup (used it for years and love it, Google it!), a bit of will to do some learn by mistakes and you can be away!
If you want any help or advice don't be affraid to massage me.
Tim