The ATPL exams are multiple guess, so are very easy to prepare for.
The reality of instrument flying, a reasonable ability at mental maths will help, particularly speed/distance/time calcs and the fuel planning.
Also a very good understanding of the rules is essential, although hard work since air law and operational procedures are the most boring subject, but bust an approach ban or fly with too few cabin crew and you are in trouble!
What are you planning to do with your Geography degree? Can't imagine it having many direct applications.