What kind of courses should I do while pursuing B.Sc for a better career? Recently I have also admitted in O level DOECE.

dear sir,
i am a 19+ yrs student of bsc pass cource of 2nd yr. and having not so good marks.after completion of bsc what kind of course to be taken/preparation for my service carrier as well better prospects.recently i have admitted in O level in DOECE. i am too much puzzled about my future carrier.