A Page within WordPress is typically used to present “static” content that doesn’t change very often. A good example of a page is the information typically contained in “About Us” or “Contact Us” pages. Pages should not be confused with "Posts", which contain blog or newsfeed content. Pages live outside of the normal blog chronology, and as such, are not displayed with the rest of your posts, but get displayed individually.
To edit an existing page, simply click on the relevant Page or Post title, when viewing your list of Pages or Posts. Alternatively, click on the Edit link that appears beneath the title when hovering your cursor over each row.
The screen that appears will be exactly the same as the Add New Page/Add New Post screen, only with the existing content displayed. When you’ve finished editing your Page/Post, click the Update button.
Login into your WordPress admin dashboard
On the dark menu bar on the left side of the screen, click on Pages
A new screen will load, displaying a list of all the existing pages within your WordPress website. To edit one of them, simply click on the name of that page.
The visual text editor will load, with the content of that page displayed inside it. The text editor works just like Microsoft Word, with familiar tools and icons to assist you in editing content. To update any text on the page, simply locate what you'd like changed, and adjust the content to your liking by selecting, overtyping, deleting, etc.
Once you are finished making your desired change or changes, click on the blue button to the right labeled Update. Your changes are now saved and visible within the page.