I don't want to discourage people from obtaining, examining and trying to understand biological data "for fun", in their own time. However, your question suggests to me that you are not quite ready to take this step.
You will learn the research skills that you need during your masters course. These include knowing where to find data, how to retrieve it, good research questions that you can ask of it and the tools required to help answer those questions.
My advice: be patient and don't try to run before you can walk.