When typing the word "Unprepared" on a keyboard, you just have to look at the buttons and find each of the ones with those labels, and hit them in sequence.
To type the word "Unprepared" on a steno machine, you need to hit the buttons UPB all at once and then PRAOEPD all at once, knowing that PB is a combo that means N, that the UPB set assumes that it's a prefix to whatever follows, that AOE represents the vowel sound /i/, and that your software understands the input "preepd" to be a shorthand for 'prepared'.
You can try it out with your regular keyboard in the browser here: http://www.openstenoproject.org/demo/