2003 Dodge Durango Transmission dosn`t work properly

I have a 2003 Dodge Durango (5.9, Automatic) that I am having some transmission issues with. It does not down shift into 1st gear. Occasionally, on cold starts, it will start of the first time in 3d gear, but after that it always take long time to shift the other gear. It up-shifts and down-shifts fine in all other gears. How do I know the cause properly
also it take over fuel to get start
also when gear start at 1st didnt take to start without fuel increasing
Kindly let me know the cause
i should be thankful