"Sighting in" a rifle is the process of adjusting sights (or telescope) so that the point of aim and the point of impact are the same at a given distance. It should be done when the gun is first acquired, whenever sights have been moved (or removed) and prior to use for hunting, shooting in competition, etc.
I recommend checking online for videos and forums to assist you in setting the sight for your rifle. With each rifle and barrell, it will differ on how the sight is set and someone with more knowledge may be able to assist you.
You sight it to a specific range , e.g. 100 meters. Clamp the rifle to a solid object, or use a benchrest. Shoot at a target and adjust the sight accordingly, until the holes in the target zero in to the sight.
Assuming you mean a Mauser 24/47, use the sight as you would any open rifle sight. The slider on the rear sight adjusts for range- marked in meters.
Should be a Stevens rifle, but the peep sight would probably be aftermarket. If you can send a digital picture of the rifle and a closeup of the sight we can probably ID it for you. sales@countrygunsmith.net
adjust rear sight up for distance
The same as you would any other rifle.
You need a gunsmith.
No
Fire one round, note strike, adjust sight to that point, fire again, repeat.
Shoot rifle. Note difference between point of aim and point of impact. Elevation can be adjusted at the rear sight. Windage (left/right) may be SLIGHTLY adjusted by tapping the rear sight in the opposite direction.
The owner's manual has instructions.
Aligning front and rear sites to aim