No problem. If you just did something goofy in the content editing window, you get multiple levels of Undo (ctl-z on Windows machines, command-z on Macs.)
If you want to revert to a previous version of a page’s content, use the ‘Revisions’ control box; it’s further down the page’s edit screen, in the same column as your content editor.
(If you don’t see a ‘Revisions’ control box, fold option your ‘Screen Options’ tab (top right of your edit screen below the black bar) and check the ‘Revisions’ box, and a ‘Revisions’control box should appear down in the same column as your content editor.)
Note: Your navigation menus do not have revision history control, nor do some other types of content that work through plugins (like ‘Testimonials’.) So if you do something really goofy — like accidentally deleting your main navigation menu — please open a help ticket and choose the ‘technical support’ option. Be sure to include in your details the date you took the unfortunate site-mangling action; we’ll restore the previous night’s version of your site online within 48 hours. Please be aware in advance that you’ll lose any content you added from that midnight forward.