Over the years, we've found with open sights, that same height above the bore line (or center of the bore) for both rear and front sights, usually puts them on at 25 and 50yards with round balls.
Thus, level is usually the first "installation".
Then, find the accuracy load, raising powder charge from just above bore size until the groups shrink, then start to expand again.
Ball .005" to .010" smaller than bore size + 10 ounce denim that we measure at .021". If the barrel has rounded rifling, you are going to likely use the .010" undersized ball and
a LOT thicker patch to fill the grooves tightly.
Adjust one thing at a time. Pick up the patches and see if they are standing up to the 'gaff'. If they are reusable with the addition of more lube, they're fine with THAT load. They might
not be fine with more powder though, as more powder raises pressure and thus is harder on the patch's purchase and sealing the gas/flame and pressure behind the ball.
Our loads seal and thus we do not need a wad between powder and ball - the patch does it all. The patch must also be thick enough to carry enough lube to wet the fouling from the
previous shot to allow loading, pushing all of that fouling down onto the powder, to be blown out the bore next shot.
The lube also must lubricate that ball's passage out the bore and leave 'some' lube in the bore to soften that shot's fouling, allowing easy loading of the next patched ball.