"I know i need to learn Java,Javascript,PHP, and Flash."
I don't know how flash snuck in there...I would put it last on your list of things to learn.
Let's assume that your site has essentially two parts: One the game itself, which loads kind of like yahoo games where people play. The other is the website where you access the game, which shows scores, has forms to submit bugs, register to play the game, forums to discuss the game, etc. Here's the role that each technology plays:
Java: This will be the most difficult and the most important...You'll want to create what's called a Java "Applet", which is a program that runs inside of a browser. You'll use Java to create your game. Once you learn the basics of Java, you'll want to focus on applets.
PHP: Second most important, second hardest (but still WAY easier than the Java portion.) PHP does the second part of your site...All the normal website things. You will have a database (probably mySQL) that holds all the users, messages on the forums, etc. PHP will look up the info in the database and display things that will change...Like High scores, rankings, messages, etc. It will also read in the information from forms that people submit and add their entries to the database. You'll want to focus on the database functions in PHP...But it's a simple language and going through the tutorial on PHP.NET should get you pretty far.
Technically, Java can do all this as well. You would use Java Server Pages (JSP) for this. PHP is more common and easier, but since you're already learning Java...
Javascript: First off, Javascript is completely unrelated to Java. Don't associate them at all. The least important and easiest portion of your game, javascript does small tasks once PHP is finished outputting the page. It can do things like validate e-mail addresses and pop up a message saying that it's invalid, move things on the screen, make drop down menus, etc.
Flash is kind of like a suped-up javascript...You can do animations and stuff in there, and even create smaller games in it.
-SN
PHP:
