How to auto-fill text fields based on static text boxes?

Hi Ryan.Oliver,

This can be done with the "Prepare Form" tool. If a similar form filed assigned on all the pages or you copy and paste the same form filed on every single page then the value entered will be auto-populated in all the fields.

Fields with the same name will automatically have the same value, so just make sure the field names are identical.

How to set the from field, for that you may check this help document: Create fillable PDF forms, PDF form creator | Adobe Acrobat DC

Or if you are looking for something like explained in this document here Automatically fill in an a text field after a selection from dropdown field in a acrobat form. (PDF Forms)  then you need to take help of java scripting.

Regards,

Akanchha