Your friend is very smart, because he suggested you to learn php.
But for learning php you need to be strong in html knowledge bcoz php is just like an intermediate (or like an engine) which will interact with the server and get you the result both from database or server dynamically, but you should be strong on what you have planned to do.
Because being a php programmer is not so tough job. You have to posses some smart thinking capability.
Try reading some designing blogs.... it will surely help you...