I took 2 tests via ikmnet and scored 70 % on SQL and 65 % on Java. While not bad, it can be improved. The subskills I need to improve according to the test are interfaces and inheritance, compilation and deployment, flow control, The java.lang package and "Java Program Construction" and these topics seems rather broad to me. Rather than just learning by programming, could you advice me to take a certification, follow a course or otherwise improve my skills?

By the way, I enjoy python more than Java so should I market myself more of a python programmer or even a role that some companies search for which seems like a system developer with more technical writing where the title is system analysts (evaluating systems in cooperation with management rather than programming.)

Thank you for any comment and/or answer.