<p>Certainly you could begin by self-study of Java in general, or the APCS curriculum in particular, if you like. The Java compilers are free for download, and there are plenty of free development environments for download as well. (If you happen to know what environment your school uses, that would be an added bonus.)</p>
<p>On the other hand, any exposure you get to programming or algorithmic development, in any language, would certainly help. You might consider playing around in some environments like Scratch ([Scratch</a> | Home | imagine, program, share](<a href=“http://scratch.mit.edu%5DScratch”>http://scratch.mit.edu)) or Alice ([Alice.org](<a href=“http://www.alice.org%5DAlice.org%5B/url%5D”>http://www.alice.org)</a>), which are programming environments that use custom graphical languages in order to build animations. It’s not programming in Java, but it can be a nice transition into Java programming.</p>