With any optic adjustment it's easy to get things backwards.... that's part of the learning curve.
The left-right markings or up-down are referring to where you want the shot to move. So if you hit 3inches right of your aimpoint and an inch high you would need to come left 3inches and down 1.
The amount of each click on the adjustment should be a known value for 100 yards which then you would have to account for at shorter or longer ranges. a 1moa click would mean 1 inch at 100 yards, 1/2Inch at 50 and 1/4 inch at 25 yards.
So if you were 3 inches off aimpoint at 25yards you could assume 4 clicks ( 4 X 1/4) per inch of movement with a 1moa adjuster.... so 12 clicks should move you close to 3 inches.
Best bet is to start at close range 10 or 25 yards and use a large piece of cardboard to mount your smaller target on to in case your not "on paper" for the first shots.
You also need to learn the difference between the sight line of the optic and the trajectory of the bullet which travels in an arc going up through the line of sight and then back down again through the line of sight as the bullet gets pulled down by gravity.
Make sure you have all the tools you need for not only your optic mount and adjusters but also a decent flat head screw to fit the screws on your lever action. They tend to come loose and should be checked periodicaly before, during and after firing. You want a screw driver head with a hollow profile and a nice square contact area to avoid damaging the screw head slots.
The irons sights on your lever can also be adjusted by using the elevator at the rear sight and also by "drifiting" the sights in their dovetails for windage (side to side) adjustment. This is best done with a brass punch and a hammer while the gun is well supported.
Iron sights are a bit tricky as moving he rear sight to the left will shift the bullet impact to the left and moving the front sight to the left will have the opposite effect moving the point of impact to the right. Moving the rear sight up will bring the barrel up along with the point of impact and the opposite is again true with the front sight.
Your going to make a bunch of mistakes and that's the best way to learn.....
The only other thing I can think of is you want to shoot groups and then center your group as the aim point... it's easy to chase around shots specially if you don't know how well you can shoot yet. So once your on paper shoot a full magazine aiming at one point and then look at the pattern you get, now imagine the middle of that pattern and that is the center of your group. From there you can measure the distance vertically and horrizontaly to the single point you were aiming at for each shot and repeat the process.