Every time you edit a page on your website, the old version is still saved. You can revert to an older version of a page at any time. Here are the steps:
STEP 1: Log in to your website dashboard (if you don't know how to do that, click here). Once you're in, click on the Edit Site button at the top and find the page you wish to revert.
STEP 2: Navigate to the page you would like to revert and click the Revisions tab.
STEP 3: You will see your revisions organize by date saved. Click on the saved date of a particular version to view it.
STEP 4: If this is the version you'd like to revert to, click the Revert to this tab. Confirm your choice and then you're done! You will need to go into the Edit Current and publish the content.
If you have any more questions, feel free to submit a support request here.