Dynamic Input DC-DC power converter guidance


I am looking to design a power converter system for a solar tracking system project. I'm a senior in EE, but have never designed anything from scratch like this. My solar panel's voltage input will vary depending on the daily weather from 0-40V, but I need an output to charge a 12V battery, power a 12V linear actuator, and power a 5V Arduino controller; the battery should also be able to power the Arduino. and actuator.

I've been looking online for several weeks for guidance but everything I see says I need to know the input voltage, but since my input voltage will vary I don't know how to use that in any of the equations I'm finding for buck, buck-boost, and voltage regulators. 

Any guidance would be greatly appreciated.