Once you’re logged in, the easiest way to edit a page/post or event is to find it on the website, then scroll down to the bottom. You’ll find a small “Edit this” link in the bottom left, just above the footer. If you click this it will take you directly to the editor for the page.
Alternatively, you can go to the “All Pages” section within WordPress, where you can browse all pages, or search for the one you’re looking to edit.
Once you’ve found the page you’re after, follow the instructions here for help editing content.