So if my cable isn't long enough and I have to extend it a few feet by getting a short cord and attaching it, should it affect the quality of the image? I'm not sure I should fool around with disconnecting that cable from the dish to replace the entire cable with a longer cable.
Adding a short piece, you'll be fine, add it, get it all set up so you can watch TV ...
Have patience when setting it up and re adjusting.
Once you get the dish set up and working, then if you decide to replace the cable that may be not long enough you can, but replace the whole length.