The commands are similar to 11, but there are some significant differences (no /item command, the range of <st> placeholders isn't there, etc.). Full list is here.
To bring up your list of macros, type /macros or bring the window up from the menu (believe it's System > Macros). If you're using keyboard/mouse hotbars, you can just drag each macro from the macro window into a slot on a given hotbar. For the gamepad, you scroll around the macro window with the D-pad, and press square to bring up a mini menu for each macro, which will have a "set to hotbar" option. From there, you set the macro into a hotbar slot just like you do with regular commands. I think it's just a matter of switching to the bar you want it on and pressing the combo for the slot you want, but the little window that pops up on screen tells you exactly what to do.