Well, in general the answer is that the only setting that controls text
direction (in tables, text boxes, and frames only) is Format | Text
Direction. But if all text is vertical when you create a new blank document,
then there's something more going on. Is your entire screen rotated or only
the text? Is the text really rotated or just a very narrow vertical line,
like this?
A
B
C
etc.
More details will help us troubleshoot.