Calculating age on a Word Document

[arojo1976]

I am updating a Word document and I would like to do the following:
1. Calculate age
2. When a Referred From is selected (using a drop menu) that the Referral Code populates with the correct code.

I've tried to read and insert formulas but I am still not getting the results I want. I am not a developer but I love creating forms and if I can make this user friendly for my clinical staff, even better. I have attached the Word document I am working on.

Please help