Acrobat can detect fields for you, specifically in Word documents. It does an excellent job of detecting where the fields should go. However, I create a lot of documents in Illustrator or other applications that are design-heavy. Acrobat does not do a good job with automatically detecting fields in those types of documents. In that case, I tap Change hyperlink and turn off Form field auto detection. Then I create the fields myself.
At the top of the document, there are Form Fields and other Form tools.