Car had trouble starting on 2003 Infiniti G35

My car had trouble starting the other day. It was parked on a sloped driveway for about a week and when I tried starting it today, it took about 10-15 turns for it to finally start. I'm thinking maybe the car is low on oil. Could this have anything to do with the car being parked a slope?

2 answers
First how much fuel was in the tank? What did the gauge register? Do you have any check engine lights on?
oil or fuel if tank was very low when parked a week ago