They were ordered foward on a couple of occasions but pulled back before active engagement. How close they came to the front lines we do not know.

They were in the combat zone and very well could have had some minor meetings of
skirmishers.

6th Alabama Infantry Regimen
July 21, 1861
Battle of Manassas (Bull Run)
The regiment was in reserve at the ford.
http://civilwarintheeast.com/confederate-regiments/alabama/6th-alabama-infantry/

…….

It was on the field, but not actively engaged in the first Manassas
http://www.archives.alabama.gov/referenc/alamilor/6thinf.html