Chosen Solution
I was goofing around with the preferences on my new Mac, and now the text capability has ‘disappeared’. I cannot write anything at all. I cannot write anything, after logging in. What have I done wrong? … and how do i correct this?
Using the trackpad you should still be able to get into Preferences control panels. I suspect you disabled your keyboard. Open the Keyboard panel, go to the ‘Input Sources’ you should have this: