Help with leave schedule

I'm looking for guidance or suggestions on how to create a vacation roster that emails each person and their manager when it is their turn to pick -- basically a form that has all the weeks listed, allows users to pick their weeks, then emails the next person when they are done. so maybe a that allows them click they are complete and sends the email to the next person in the list.

The guideline for the selections would be user have 3 rounds to pick

First Round - they can pick 1 or 2 consecutive weeks
Second Round - they can pick 2 weeks consecutive or if 3 weeks are chosen then 2 weeks consecutive and the 3rd split. if only 2 weeks are chosen they can not be split.
Third Round 2 consecutive or split weeks.

Maybe what I have attached is a start, but I'm not sure that is even a good way to approach it.

The final document will be on a sharepoint page or shared drive for everyone to access if that changes anything in the process.