It is easily to make animation of single object But It is a lot easier to move it with motion path key. It is used to join two objects with each other applying Motion Path.
First of all select CV curve tool from create> CV curve tool.
Draw a curve as you want. Now choose polygon sphere from shelf tab
The sphere will move in X-axis. Set a key there. Red color arrow is for x-axis and Y-axis is for up movement.
Now go to animation menu set and animate> path motion>attach to path motion.
Sometime the animation follow the current time range, so first of all set the time range according to your need. Usually it has 24 key frames which is equal to 1sec of time. You can set it in TIME SLIDER check box
The front axis shows its X-axis and the top axis for Y-axis. Set it corner and bank as you want.
If you want to change any setting, you can do it. Simply go to Attribute editor and reset the movement path. In Attribute editor click on tab motion path and update the setting.
Finally play your animation.
For example you are making simple animation of ball on zigzag path. Now set a key from key frame on it’s up and down points. And join and move them with Motion Path and attached Motion Path. Now it will move in zigzag position.