Welcome to PF;
A good start is to look though your course notes, or to google for information about force work and potential energy.
If you sincerely have absolutely no idea at all where to start - then you have more serious problems than this.
Start by describing the energy transformations at each part of the journey.
Take a shot, Miyla. Do one part at a time and we'll help. Start with A. I can't help but notice none of your equations say anything about the spring. What have you been taught about a spring?