The dashboard is the starting point for updating the website.
There is a menu on the left hand side and you will see among the other items that there are sections for Posts and Pages.
Posts and Pages
WordPress began life as a blogging platform and so it still uses the concept of posts and pages to organise information. It may take some time to fully appreciate the difference between posts and pages, but for now this definition will do
Pages are used for static information that changes rarely (the contact page, about our organisation etc.)
Posts are used for time based information (News, what’s on, events and so on). Posts can be categorised (Kids, Environment, News, summer, or whatever you choose.)
Adding categories to posts is an important way of organising your site, and is often used to automatically add posts to lists of content such as ‘latest news’ or ‘what’s on’. WordPress has a method of presentation called a category archive that gives a listing of all the posts in a particular category.