Output voltage control with Arduino

My task for this project is to increase the output voltage by one after each 1.5 second till 120 V. How can I do it from software and hardware point of view ?

Very, very carefully.

How many amps?

AC or DC?

Do you already have a power supply capable of that voltage and current?

Any other rules? What happens when it gets to 120V? Do you need to start, stop or reset it?