I am a software engineer who has used Java, C, PHP/SQL, HTML, and Ruby on Rails, for projects in college. Right now I code in C.
PHP is a scripting language that takes Java, C, and HTML. Typically PHP is used for dynamic webpages. Though it does use HTML (actually, it processes HTML), you still cannot get away from some of the elements that Java and C utilizes - variables and information passing for example. PHP uses classes for example and has its own syntax.
What you should ask yourself is: do I want to work with webpages.
But coming from someone who has been where you are now, you need to practice programming to become good at it. From just one course, all the concepts and ideas used will not make sense. It took me 2 courses to understand what a class is. As a Teaching Assistant for 3 Java classes, the people I see fail typically are people who are not willing to practice, analyzed, and make mistakes. They typically expect a formula and process, like math, to generate an answer.
I hope that helps! :)