Hi Cian O’ Callaghan,
For the default pages you and edit the page by adding the different blocks. You can get Block elements from click plus (+) icon on left top of screen or from the page content that you can even see on your screenshot as well.
But If you are using Front Page Template on Home Page as our Demo Site then you have to add and edit as widget and other component from the ‘Appearance > Customize’. you can also check Video Tutorial to edit Front Page Template
Thanks