Your TV subscription is available in the EE TV app from within a few minutes after your order (you don't need to wait for activation date), however you need to claim your account.
As your broadband is with EE, you need to add your account to your EE ID.
Log into https://id.ee.co.uk/ and then select the option to "Add a device" (yes, I know, it's odd wording). From there, you can add your EE Broadband account to your EE ID using your account number. After you've done this, the EE TV app will start working.
Your entertainment subscription includes access to Now TV, where you'll find content available to watch. You will have received an email asking you to set a password. If you don't have it, simply visit nowtv.com or install the Now TV app, and request a password reset.
