user17439: I have this problem where when I add a camera layer, my composition disappears (but only when the view mode is set to Active Camera). How can I fix it?

I also have problems zooming in on just a part of the composition. Like from wide view to a specific layer.

user17439: It seems I was a complete noob ( for I am new with After Effects ). I couldn't see my composition because the blur on the camera was turned to 100% and everything was completely out of focus. Also, I couldn't zoom in on a specific layer because the camera was underneath them. This video helped me a lot to understand the way camera works in Adobe After Effects, and I wish I had found it earlier because I am dealing with this problem for a while now.
Thank you @JasonConrad for trying to help! 

17439: <p>I have this problem where when I add a camera layer, my composition disappears (but only when the view mode is set to Active Camera). How can I fix it?
<a href="https://i.stack.imgur.com/IJkBI.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IJkBI.jpg" alt="enter image description here"></a>
I also have problems zooming in on just a part of the composition. Like from wide view to a specific layer.</p>
 17439: <p>It seems I was a complete noob ( for I am new with After Effects ). I couldn't see my composition because the blur on the camera was turned to 100% and everything was completely out of focus. Also, I couldn't zoom in on a specific layer because the camera was underneath them. <a href="https://www.youtube.com/watch?v=Axa38beTBvo" rel="nofollow noreferrer"><strong>This video</strong></a> helped me a lot to understand the way camera works in Adobe After Effects, and I wish I had found it earlier because I am dealing with this problem for a while now.
Thank you @JasonConrad for trying to help! </p>
