Camera problems in After Effects 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.
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!