New to Java

I am interested in learning how turtles work in java...
I had looked around for some examples, and whenever I try compiling them it always says something about not being able to find the symbol class....
can anyone give me a quick run down as to why this might be happening? ive been reading up on it and I think it might have to do with classpaths? I only have found example codes and assume that would be all I need to run them...
help please?
-thanks