Choose a language that works on your computer at home or at school so you can see how good you are. It'll help your learning curve enormously.
There are thousands of free websites for "newbie" programmers out there, and they all have forums where people like you can ask for help, and even post their problematic code for some guidance from the wise and experienced.
The best thing you can do to make sure you keep up with your new skills is to write programs that directly impact your well-being: whether it's tracking grades, or mixing music tracks to create new and random "theme" CDs--the more real life applications you write, the more likely you are to keep writing. Almost every great program not written by a software behemoth was written to fill a personal need--who says you're not sitting on the next great program?