Hello
I just bought an infiniti g35 2003 model
When I ride the car its little bit hardness I'm feeling to steering the wheel
And also
When I try to turn on the engine at first ignition on there is a service engine soon light on and after turn the engine on it will turn off, is it a major problem?
Please let me know?

Not sure what you're describing in the steering.

The check engine light is supposed to come on when you start the car and then shut off a few seconds after the car is running. Sounds like it's working fine.