I am trying to complete the design of my homepage and I am not happy with the layout (size/positioning/font of the header and subtitle - "Carcassonne Townhouse" and "Luxury Bed&Breakfast | Chambres d'notes") overlaid on the hero image.
Is it possible to customise the font just for this title and subtitle without affecting the rest of the site? Or is it possible to turn off the overlaid title (like you can have no subtitle) so that I can replace the photo with an artworked photo with the copy positioned as I would like it?
You can customize any part of your site adding some custom CSS (Customize -> Additional CSS). Use the Chrome inspector to find a CSS selector and apply your CSS.