You left the car on and ran down your battery - maybe to the point where you will have to replace it.
You made some mistakes with your setup. Since your Demco tow dolly has pivoting wheels, you can place your Avalon on the dolly, tighten the straps, put the transmission in park (leave the emergency brake off), remove the key, lock the doors and have a nice drive.
2017 Winnebago Navion 24V
2014 Tiffin Phaeton 36GH (sold)
2012 Tiffin Allegro 32CA (traded)
2012 Honda Fit