1. Congrats on ur new purchase
2. Just relax and enjoy it just as ur previous cars
3. The engine oils are different for diesel engines from petrol
4. The oil change interval would primarily depend on ur oil quality and secondarily on ur running habits/ conditions.
5. Do change the oil regularly and change the filter with every oil change if u can afford to do so.
6. Before going for the automizers, u should check that all the filters including the air, diesel and oil filter are changed. Get a fresh oil change. If the problem persists, Get the tappets adjusted. Get the fuel injection pump timing checked by an expert mechanic. Check the engine compression,m and then move towards the tappets and fuel injection pump.
7. If the smoke is not much, then u can live with it. but if it irritates u too much then proceed as above.