What I have to do to become a good student?

Well you're not a kid any more so we're talking university student here, right? First of all, enjoy your student life - join lots of clubs; play sport; have a broad social life. Try to give a bit back to the uni by supporting events they sponsor. As far as studies go, appear to be interested in your tutors and what they have to say. Sometimes challange their statements if you feel strongly on a subject but be prepared to accept that they can have different views to you. But overall, enjoy yourself!!