I don't have the toolbar on the left nor the info panel on the bottom as shown in this video. I've looked through all of my settings and can't find anything that turns these on or off. I must be missing something because without these I cannot scatter assets at all!
You need to first click the assets button in the top left, the one with the tree. From here you can use the multi-place asset icon, the multiple trees stacked on top of each other. This should get your screen looking how the video is starting.