First things first..Before going to the range tomorrow, before you load the rifle before you do anything else ensure the bore is clear of dry hard lube , wasp nests anything but a light coat of oil. Ensure the action is lubricated and if yoou can remove and disassemble the bolt make sure the firing pin channel is clean.
To use a peep sight you look through it basically ignoring it and focus on the front sight. The reap sight will blur out to a fuzzy ring. The great thing about peeps, especially for those of us approaching or past the half century mark is that our old eyes do much better because we are focusing on the front sight and not bouncing back and forth front rear target.
Adjustments....move the rear sight the direction you want the group to move. elevation is controlled by the big fillister head slotted machine screw on the top of the sight. There will probably be some elevation hash marks on the right hand side and you will have to play a bit to determine up and down with respect to adjustment screw rotation. Windage is adjusted by the slotted fillister head machine screw on the left of the sight. Again sight adjustment direction with respect to screw will have to be determined.
The removable apeture disk should be gently snugged up against the sight. If you dont it will eventually find its way out of the sight and on to the ground If there is sufficient light the removable disk should be left in place. In the event of shooting in low light remove the disk and use the big apeture as a ghost ring with no loss of zero.