You are OK. The Photography plan is an incredibly cheap way to use Photoshop. It also gets you Lightroom and Bridge. Enjoy
The photography plan includes Photoshop & Lightroom and is nearly 50% cheaper than a single Photoshop subscription. You can install Lightroom or not, just as you like.
If this is your first order you can cancel within 14 days an get a full refund.
Please don't forget to read the terms and conditions: http://www.adobe.com/legal/subscription-terms.html