It should show the cooldown of the ability (ex: #showtooltip Charge), that's kinda strange. Be sure you haven't typed something wrong.
Don't stancedance manually, use your macros. I have got a keybind reserved only for Battle Stance, while I switch to Defensive Stance or Berserker Stance only when I'm using an ability which requires it, but I can still use my macros to stancedance without activating the single ability. For example, if you have got a macro for Shield Block which includes the "/cast defensive stance" command, pressing it only once and not too hard it will change your stance without activating Shield Block (be ware that you HAVE TO install the snowfall keypress addon, it's mandatory!) or you can keybind all the stances, it's a matter of personal choices.
Blackrock is not exactly the most friendly community for a new player. You can learn by watching better players with the spectator addon but it's almost impossible to find some good willing arena partners if you are not playing with your friends already.