im having problems with understandin ultimate facebook

i really dont now were to began, i have created a facebook page uploaded the images, etc, now on the blog , i click on the Facebook icon on the left and it brings me to a screen to follow steps , but the step are unclear well at least to me i dont know what any of this means :To do so, follow these steps:

Create your application
Look for Site URL field in the Web Site tab and enter your site URL in this field:
After this, go to the Facebook Application List page and select your newly created application
Copy the values from these fields: App ID/API key, and Application Secret, and enter them here:

Once you're done with that, please click the "Save changes" button below before proceeding onto other steps.

Please, enter correct Facebook API settings

so i go to the Facebook page to start and im lost on were to start