Animation Rigging/Rig Builder Problem

I'm currently trying out animation rigging and trying to get my character to hold his gun in a pose near his chest when the gun is not being used. But when I add that Rig layer into my Rig Builder I lose all control of moving and I can only look vertically. So confused cause I don't understand why the rig builder won't let me move around or look horizontally. Thank you for your help.