help filling out I-131 - Parts 1, 3 and 7

Hi all,

Need help filling out I-131 - much help is appreciated to all who respond

In Part 1, note 1 it is asking for a "A number" what is this? I am not sure as I am including this with my AOS package

Also,

In Part 3, notes 1 and 2 are asking me for the following:
(1) "date of intended departure" and;
(2) "expected length of trip"

If this document is to be used for multiple trips, do I put "more than one" for (1) and leave (2) blank?

Also,

In Part 7 it is asking me for additional information. Any idea how to handle this? I want to travel to see my family for periods ranging from 1 day to max. 1 week

Thanks all for your help