Will I need an oil change?
 

My car got an oil change in early July, but it will be sitting until Sept.5th. Do I need to change the oil again before I drive it?

Depends on where or how you're planning on storing the car. You should at least change the oil before letting it sit for a long period of time. If you can, a periodic startup would also help keep some oil on the upper part of the engine instead of resting at the bottom of the oilpan.