To access the Smart Assets, you have to go to your 3D World and click + Asset Library.

Then click Assets tab. 

What's great about this page is you can select an Asset and see a little preview of it in the upper left right hand corner. 

Lets go ahead and play with some of it and see what we can come up with. (click here to see the article where I used Point Asset)

For starters, lets try these 3 Smart Assets:

To use them, just select the assets that you like and click Add to Library. 

Or you can drag them to the Assets panel on the left side.

To go back to your 3D World, you can click any of your Assets or the X button highlighted in the illustration below.

Lets go ahead and drag the Position Cube to one of our scene.

Then move and scale it as desired. 

Now lets give this object a Distance of 300 while we leave the End Position at 4 on the X axis.

Let see how it previews.

Lets try and see if we can make something more fun out of this.

In the below illustration, I changed the End Position to 1.2 and pressed W to duplicated upwards. Then I pressed A to duplicate to the left and set the end position -1.2 then duplicated upwards. Remember, you can duplicate using W,A,S & D.

Let us move the Position Cube and drag the Rotation Cube inside our scene.

Then let us move, scale and preview.

Lets try something else with this Cube. 

I will scale it and duplicate it. Change the end rotation to 630.

Now let us try the Scale Cube. Let us drag and drop it to our scene.

And make adjustments to it.

We can also make the movement slower by changing the speed in the nodes.

You can do that by double clicking your Asset.

And it will then open the Assets page where you can see the nodes that bring your assets to life.

In the illustration below, you will see that I selected the Rotation Animation node and changed the speed from 3 to 1.

And that's it. There's plenty more combination that you can try and use. It is up to you to play around with it.