Always make sure you save your changes by clicking the save button in the top bar of the editor. When you want to see a quick preview of the page you can click the preview button. There is also an option to preview the entire publication. You will have to go to the page overview to do that. To preview the entire publication you have to publish it first. The publish button can be found in the page overview and in the editor. That way, when you edit a small part of a page you can directly click publish to sync these new changes to the publication.