You can place any layout element onto your designer canvas to get started. Here's a run-through of each element and how they work to contain your content. Once you have placed your element you control the properties of the element to adjust things like size, space, font, etc.
Column
Columns are used for grouping content vertically. Just drag and drop it onto your canvas.
Row
Rows are used for grouping content horizontally. Just drag and drop it onto your canvas.
Prespaced Row and Column element
You can also choose to add a pre-spaced element that is made up of rows and columns to speed up your build. You can then add additional elements if you wish to. Just drag and drop it onto your canvas.
Properties
Once you have placed your element, you control the properties of the element to adjust things like size, space, font, etc.