Danny for a .50 caliber get a .490 roundball and a .015 patch thickness. Since this is plinking for the time being, get the pre lubed.. Ox Yoke makes good patches as do Thompson Center (since I think they are Ox Yoke). You might get a round ball head short starter as it makes seating the roundball a lot easier.

The rest is the same as loading anything else. Dump your powder charge, set a patch over the muzzle and a roundball centered on the patch. Then with the short nose on the roundball starter drive the patch and ball under the muzzle, and with the longer nose, drive all this further down. Then just set the ball on the powder charge with your ramrod....

Low charges will keep the patch and ball from skipping the rifling and accuracy can be very good out to 50 yards and even further.