If you are looking for a minor job such as mcdonalds or another fast food restaurant and want a fair pay, you will be able to work at 14 years and 9 months old, if you are looking for a more complex job such as an architect, you will have to wait until whatever age you graduate university with a diploma that is open to that courier.
It depends. Did you want a part time job or a full time one? For a part time job some places usually employ at the minimum age of 14 and 9 months. For a full time job about the age of 16, although you would then have to take school into account then. Hope I helped (: