flex plate or starter

Is it cranking at all trying to turn over?

It's not trying to turn over. It's not dead battery.

be sure you are getting good spark and have good fuel pressure from there you may just be having starter problems! typically you will here a clicking sound if your starter is going bad/is bad due to it not cranking enough to turn the motor over. Also I wouldn't forget about an alternator although you did mention above that the battery is charged this could still be an issue! Answer back here and let me know if any of this help please.

I've had the truck for about a month now, it has almost 160k miles on it. Typically when I would go to start it after it has sat for a bit it would act like it wasn't getting a good spark on the initial turn of the key. But if I would turn it again it fires right up. The more I think about it I think it would be extremely difficult to damage a flex plate.

Yea is your Durango fuel injected? if so check that you have getting 40lbs of pressure in your furl rails if your not the injectors wont open also might just try a simple tune up! if there is not 40lbs of pressure I would recommend a new fuel pump.

fuel rails*