The Personal Information page is the section of the admissions application where you provide the campus with some background information about yourself.
Here's a brief overview of some of the fields on this page:
Preferred Name: If you go by a different name then what you've indicated in the First Name field please indicate that alternate name here
Previous Name: If you've changed your name in the past enter those previous names (as many as necessary) in the "Previous Names" section of the form
Date of Birth: Either type in the date or use the pop-up calendar to enter in your Date of Birth. DOB helps the campus determine your residency requirements.
Form of Identification: It's OK if you don't provide the campus with a form of identification - but it can slow down the admissions process as this information helps the campus match you to other documents (transcripts, test scores, etc.) as well as to ant financial aid information you've submitted