Rigid body animation is perhaps the simplest of methods for moving any thing around your stage, including Sketches, Shapes, Props, Vehicles and Characters.
To start, point at the thing you want to animate, press the Inspect button and select Start Motion from the Inspect Menu. (This step is not needed for character puppets as they are always animated.) This will create a keyframe on the Timeline.
You can now scrub the timeline and use the Grabber to move the thing to create a new keyframe. When you scrub between those keyframes, the thing will move: it will follow a smooth spline between the points and uses speed curves to start and stop smoothly.
Build up your movement in stages: For example, place a car, then move time and place the car a second time to create a straight motion path between those two points. Then scrub the motion path to points where the car is not moving naturally, and re-orientate the car to create new keyframes in between. Alternatively, the same technique can be applied by scrubbing on the timeline.
You can change how the animation behaves between keyframes, by going to the Timeline, pointing at the animation and pressing the Inspect button: then choose the Edit option in the pop-up menu.
You can now see the properties for the animation:
There is also an action, Set Constant Speed, which changes the timing of the keyframes so the thing travels equal distance in equal time.