You can manage 301 redirects under Settings → 301 Redirects. Send visitors from an old path to a new one, including query strings on the public site. Changing a blog or page slug automatically creates a redirect from the old address.
If you redirect a published blog post, you’ll get a clear warning and must confirm; saving unpublishes that post so it leaves the blog while visitors go to the new URL. Flo can create and delete redirects behind the same Confirm approvals you already use.