My 300 won't start sometimes but when it does start it long cranks then starts. It is a automatic as I'm driving it doesn't shift gears. My check engine light blinks and make a beeping noise. Any ideas what could be wrong?

No ideas here, but there is plenty of information available during hands on diagnostic testing. Your check engine light, for example, indicates diagnostic trouble codes related to some of your concerns are stored for analysis -- to help troubleshoot what is happening. The blinking check engine light and beeping noise is telling you to not drive the car! Have it checked right away to prevent further damage from occurring.