DixieTexian is pretty much on the mark.
Actually, I hope you got 0.015 patches - 0.15 is just a little too thick.
Start with No. 11 caps. If they are loose, use No. 10's. It's not always obvious that a No. 10 is too small, so it's better to start with the bigger ones. Also, although this is a fine point, the No. 10 and No. 11 size is not necessarily rigidly controlled between manufacturers and between nipple makers; you might also find that changing brands of cap will provide a better fit. The idea is to get one that is not loose enough to fall off but still large enough to go all the way down on the nipple so the ignition material is against the top of the nipple. That last part is not so easy to discern.
As for ball, patch and powder, you got the right stuff to start (assuming the patch dimension is a typo). The patch should be a lubed patch, or moistened with Bore Butter, spit, etc. Lube is important to help keep the bore clean longer. Swab the barrel between shots with water or bp solvent; whether it's between every shot or every other shot or every fifth shot or whatever will need to be worked out. Use 90 gr 2f at first until you get used to shooting the gun - it'll pay off in accuracy later as you are less likely to develop any bad habits.
And try to keep the grin under control.
