You won't be able to reactivate your account.
Your profile, photos, posts, videos, and everything else you've added will be permanently deleted. You won't be able to retrieve anything you've added.
You'll no longer be able to use Facebook Messenger.
You won't be able to use Facebook Login for other apps you may have signed up for with your Facebook account, like Spotify or Pinterest. You may need to contact the apps and websites to recover those accounts.
Some information, like messages you sent to friends, may still be visible to them after you delete your account. Copies of messages you have sent are stored in your friends' inboxes.