Dear Mr. Bernabe,
Thank you for posting your request on History Hub!
Sometimes the instructor of a training facility paid for a civilian photographer to come to the military base to take pictures. These photographs may have been filed in the records of the unit but oftentimes they are just distributed to the individual members with no permanent copy kept.
If a group photograph was taken by the Army Signal Corps or other official military photographers usually for publicity, the photographs would be considered permanent records and are part of the photograph collections in the custody of the National Archives at College Park - Still Pictures (RDSS). Please contact RDSS via email at firstname.lastname@example.org.
We hope this information is helpful. Best of luck on your research!
What year and do you have unit information they have lots of alternate sites for military yearbooks.