Welcome

I just hope you run a handicap system :D as it's been years since I coded in Java

That's not an excuse. Robocode was my first ever experience with Java. This wiki is a huge Robocode knowledge-base, and there are many open source bots from which one can learn very much. Also, if you want to try limited Codesize development, I could give you many pointers and tips.

Welcome from me as well, and best of luck.