+1 on the advice of the previous posters. Let me add some simple practical steps that will help you get started with some early successes.
Do you have a place to shoot out to 600 or 700 yards? If so:
Build yourself a target stand out of 2X4s about 6' tall and 30" wide with a base so the uprights will stand up where ever you sit them. Use builders paper (available on a roll from Lowes) Roll out about 5' of paper and staple to the target stand. Now you have a target area that is 30" wide and 5' tall. This will keep you from missing the entire target at longer ranges (mostly anyway
) and wondering where did that one go?? Stick one of those 3 or 4 inch stick on target dots about 1' from the top.
Set up or build a good solid table or shooting bench. Use sandbags or better yet invest in a pedestal front rest and rear bag. Get your rifle solidly in the rest. dry fire it 20 times paying close attention to any movement of the crosshairs to check for any twisting or flinching when breaking the trigger.
Set your target stand up at 100 yards, shoot a 3 shot group. Move it to 200 shoot a 3 shot group.......etc to whatever your max range is. Use the same aiming point. this will give you a fairly accurate drop chart for all the ranges.
To get rough dial up values you can do the math or you can try the following trick. With the target at 300 yards, place a second target dot at the center of your 300 yard group which will be several inches below your original dot. Now, put your crosshairs back on the original dot, then while holding the rifle steady dial your scope up (the crosshairs will move down) until the crosshairs are now on the dot that is the center of your 300 yard group. That is how much you will need to dial for 300 yards. This can be repeated for each range. (this is rough approximate drops and will need to be fine tuned with a few more groups at each range)
Moving a large target area like this out to ever longer ranges you will probably be able to keep all your shots on paper and work out quickly what your drops are and what the capabilities of you and your rifle are. You may be surprised at how well you can shoot at the longer ranges. As you get on past 500 yards you may want to start moving your target in 50 yard increments. Also remember to shoot 3 shot groups ALWAYS. At this stage in your LR development you do not need to draw conclusions or make scope adjustments from just one shot. You may eventually get there, but for now use the center of a group for your data point, not a single shot.
This is all pretty basic stuff, if you really get into this LR stuff you will eventually want to invest in lots more toys like a chronograph, ballistics program, high end rangefinder, etc, etc, etc.......
But for now these simple steps should get you some success at 500 to 700 yards without any major investment above what you already have.
Have fun, keep reading the wealth of great info in the archives on this site, and welcome to the forum.