Create the object you want to animate using the tools on the "Create" and "Modify" command panels. If you create multiple objects, such as a mechanical assembly or a multi-component character, make them follow the path in the same manner as a single object by turning them into a "Group." Select the objects and, from the "Group Menu," choose "Group." Give them a name.
Select the "Create" tab, then the "Shapes" icon, then "Line." Click a series of points to define the path you want the object to follow. Select the "Modify" tab, choose the "Edit Spline" modifier, then choose "Vertex." Move the vertices of the line to adjust the shape of the path as required.
Select the "Hierarchy" tab on the "Command" panel. Select the "Pivot" button. Select and move the pivot point on the object to the location where you want the object to touch the path. For example, on a roller coaster cart, position the pivot point on the bottom of the cart.
Click the "Time Configuration" icon located in the lower right corner of the screen. Specify how many frames you want in your animation. Choose "OK" to exit this window.
Select the "Motion" tab. Click the "Assign Controller" icon. Select "Path Constraint." Click the "Pick Path" button and click the path you created with the line. If you click the "Play Animation" icon, you will see your object follow the specified path.