Why is the text disappearing as I type?
By default, any new text you enter in the middle of a line is inserted by placing the text in-between the characters on the left and right of the cursors location, in essence pushing the other characters to the side.  This can be switched so that text is overwritten as you type by going into Insert mode.  If existing text disappears as you type, Insert mode may be turned on. On your keybord press the Insert key to change to the default mode (Insert Type).

Missing Cursor

I was working with text and went to change the Font Face and I suddenly lost the cursor. What happened?

When you select a dropdown box and cancel out of it by selecting elsewhere in the screen often the browser will retain the focus on the dropdown.  This can have the effect of making it appear that you have lost the cursor.  If you look at the dropdown box of the option you were just using you should still see it selected.  Click once again outside of the dropdown on an empty area of the page.  This should release the selection allowing you to place the cursor where you would like to edit once more in the page.