Simply so, can I re enter Canada with a study permit?
You can leave Canada and return, as long as your visa or Electronic Travel Authorization (eTA) is still valid. Your permit (study or work) is not a visa and doesn't allow you to travel back to Canada.
Furthermore, how early can I enter Canada with student visa? A normal stay is up to six months, though presumably on seeing your study permit they will admit you for the duration of your course. So in short you should be able to arrive at any time before your course and be admitted.
Secondly, can I leave and re enter Canada on a work permit?
Leaving and returning to CanadaIf you are still admissible, the border services officer will allow you to re-enter Canada with your original work permit. The work permit states “This does not authorize re-entry.” This means the permit allows you to work in Canada after you have been legally admitted.
Can I travel with study permit?
Yes. However, your study permit is not a travel document. It doesn't give you the right to travel to or enter Canada.