Cutting out the truck and trees would be pretty straight forward. Just find equivalent vector art in whatever format your laser likes. Online trace and format transformation websites are available to help with that step.
To make the truck and trees stand up, you will need to add a square tab to the bottom of each tire and to the base of the tree's trunk. This tab will fit into slots which you cut in the disk portion of your project. Inkscape is a free vector editing software which is good at making these kinds of modifications.
Just make sure to measure the thickness of the wood you are cutting all this from, and use that as the width of the slots you are cutting in disk. That way, the tabs which you have added to your upright pieces will fit snugly into those slots.