Admin and front-end
Your website is splitted in two areas: administration and front-end. The administration area is where you create the pages and the menu, and where you insert all the contents of your website. The front-end is the result of the admin content and is the final website that the users will visualize. You will build your website in the administration area and you will see the result on front-end area.
Build your website - basic instructions
You can build your website by using only two components: the pages of your website and the menu. The pages of your website are at WordPress menu > Pages. You can edit them by clicking on the title. To see the final result (the front-end), click on Preview button on right (or Preview Changes on top of the page). If the changes are correct and the pages show good you must save it by clicking on the Update button on right (or Save Changes on top of the page).
Build or edit a page - basic instructions
All the pages of your website are a combination of components like texts, images, videos and more. When you are in the administration area of a page you can see the icons that allow you to add new components. You can build your pages by adding these components and by inserting the content you want into these components.