Hi @Amber_Cummings, welcome to the Asana Community Forum and thanks for your feedback!
We recommend users to create one thread per request as it’s easier for everyone to cast their votes for a specific feature request and for us to follow-up on 
We already have a thread on this topic so I suggest you to upvote for this feature here:
Ability to copy sections including all tasks in that section
In regards to your request to add a due date to sections which would then apply to all tasks under the section, this is currently not possible but as a workaround, you can multi-select the tasks under the sections and a due date to all at once.
I hope this helps!