Turned off won't start now it will crank but
This can be a number of different issues for your 2008 Dodge Avenger. If the vehicle will crank, that is definitely a place to start. As you may know, in order for your vehicle to start, you need to make sure it is getting fuel, air, and spark. You will want to test a few things related to these three items including the fuel and ignition systems. Depending on your experience level and access to the right tools, you may want to consult a qualified mechanic, such as one from YourMechanic to diagnose and repair the starting issue for you.