Want to know what an infantry platoon and squad does? Here's 826 pages: https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/ATP%203... .
What about an infantry company? Here's 618 pages: https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/ARN8519... .
And those just cover the basics of organization, movement, attack, and defense. Want to know how to call in artillery support? Here's 256 pages: https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/ARN2193... .
92 pages on military deception: https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN15310-FM_3-1... .
192 pages on recognizing aircraft by sight: https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/ARN3274... .
146 pages on "Army Ceremonial Music Performance":https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/ARN3102... .
There's just a ton out there if you want to dig around: https://armypubs.army.mil/ProductMaps/PubForm/TC.aspx .