You will be able to add the decorations you wish to your website thanks to the various blocks. By droping a Widget block onto your website, you will be able to add custom shapes with the Widget/shapes (rectangle, round, tooltip, stars...) or custom ribbons with the Widget/Ribbon title block. You can choose the color and style of your shapes and ribbons, as well as the color and font of the texts.
You also have the possibility to download files from OpenClipart. To do so, add an Image block to your website and in the file manager, select Public files on top of the screen, then OpenClipart on the left. You will then be able to search for the image you want using keywords and add it to your website.