Hi Flora!
So sorry the link isn't working. The title of the article is "What is the difference between Save and Publish in the Site Designer?" so feel free to search that in the Knowledge Base.
Your site has to be published before your changes show on the front end of the webiste, for example, in Preview. Your changes should show in the Site Designer as long as you click the "Save" button.
Best,
Bailey
Client Success Consultant