Orderly = Orderly Sergeant = 1st Sergeant. That means he kept the company roll book and other records.

The name should be understood as G M Jordan. As of Mar 5, 1863, he was commissioned 2nd Lieutenant of Co F, 23rd Alabama Regiment. He received a parole at Montgomery AL in late May 1865, so that answers one of your questions.

Any indication as to where this man lived? Cannot locate on the 1860 census.