For me, the most important thing is always simply understanding who has what role in the company. When I have a question, knowing whether I ought to ask my direct manager, other colleagues on the team, a subject matter expert, other management teams, our sysadmins, etc. is the most difficult thing to figure out. It can take months sometimes.
Can we push back the deadline for the apocalypse? Have we talked to the customer to see if this is a possibility?