When you publish a TED-Ed lesson page, you'll receive a unique URL for your lesson page. Only you have access to this link, and it is not listed in site search on ed.ted.com or indexed by search engines. Anyone who has the link to your lesson page can access it.
To get your lesson to your students, simply share the lesson link with them in whatever way works for you. As students submit work on your lesson page, you'll be able to monitor their progress, view their answers, and send them feedback.