Monitor the oil level to make sure you are not losing too much of that, and do NOT let it run out! A puff of smoke upon start-up could be caused by valve guide seals allowing some oil to leak down into the cylinders while the car is parked and not running. This would be pretty common on a nine year old car and should not, in most cases, be cause for concern. Just make sure it’s not burning a gross amount of oil (gross to me is more than a quart every 1000-1500 miles), and if your oil loss is minor to minimal, I would just live with it. Just monitor the oil level and add as necessary. That is probably where your little puff of smoke is coming from.