If there are channels you want to add as favorites or hide because you never watch them, you can do that on the Fire TV by following these instructions: 

From there, you can find the channel you want to hide, and press the Play/Pause button to hide it and "Select" center button to favorite.  Repeat for each channel you want to hide. The next time you go to your guide, you won't see the channel. 

Here is a great video that shows you how to do this.  https://youtu.be/Vmye_asl5Oo

Plus more Recast free training videos here: https://www.youtube.com/playlist?list=PLYk9p07pZtp3ax4Rk4eDtNacduNYhI007