The top of an affidavit and the closing of an affidavit are the same if it is one page long, or many pages long (a simple form I use where I practice is below, although some places expect something slightly more elaborate). In a multi-page affidavit it would be customary to have page numbers and to number each paragraph sequentially, but there is really nothing else that is different. It isn't required to initial each page, but it wouldn't be uncommon for an affiant to do so to avoid efforts to falsify pages before the last one.
AFFIDAVIT OF JOHN DOE
STATE OF ILLINOIS )
COUNTY OF PODUNK )
I, John Doe, the Affiant, being duly sworn, state that the following statements are true to the best of my knowledge and belief.
I am 93 years old.
. . . .
. . . .
. . .
The UFO conspiracy then paid me $666.00 in pennies under the Eiffel Tower.
Further affiant sayeth not.
Sworn before me this 3rd day of June, 2019 by John Doe. Witness my hand and my official seal. My commission expires: _________________.
The most common standards for court documents in the U.S. (although there is not one uniform set of standards) is 8.5" by 11" paper (taller top to bottom than it is wide); Times New Roman, Arial or Courier 12 point font; double spaced; one sided; half inch side margins and one inch top and bottom margins; left justified or fully justified; black ink typewritten portions on a white background and no highlighting, with handwritten portions in blue ink with a ballpoint pen. Some courts require recycled paper. If it is going to sit around for decades, use acid free paper or it will turn yellow and become brittle. Sometimes the heading is typeset rather than typed, but that usually isn't necessary. The current practice is to disfavor embossed seals as they don't scan and photocopy well.