This page will only appear the first time you're setting up a form. Select from one of the listed options. Keep in mind that what you see here in this document may change over time, as more options become available.
Note: Once you've made this selection, and move on to the Composition tab, you will not be able to change this choice. You'll need to start over with a new form if you decide the layout isn't what you're after. However, you have plenty of editing choices in the Compose tab, so you may still be able to edit your choice to a degree and get the form you're after.
Still, you want to make your choice carefully. At this point, the only way to change form layouts is to delete the form and start over. If you need to, you can go back to the Setup page and select the cogwheel icon in the lower left-hand corner to bring up the Delete option.
Once you're sure you've made the right choice, you can click the "Next: Composer" button in the lower right-hand corner of the screen.