I would try to find a club near me, or someone near me who could help me get my rifle sorted out. Exact addresses are not necessary, but to post an area accessable to me, as in "anyone in the "X" area who is willing to help me get started, please PM me" - would be a step in the right direction.
Gleaning what you can from a site like this, is also a step in the right direction. Searching for loads listed in previous threads using the search function can also provide the information you need.
Generally speaking, the .50s I've had and see frequently, use a ball that is from a .495" mould, with a 10oz. denim or .020" to .022" thick ticking patch, with 85 to 100gr. of 2F powder. Some people prefer to use 3F in the .50's. You will see recommendations in powder use from 50gr. to 110gr. in 2F or 3F.
Note that about any load will cut a single small hole for 5 shots at 25 yards - even a smoothbore with only one sight. In order to find an accuracy load for your rifle, you need to shoot at 50yards minimum and even further is better.
The crown (top of the muzzle) probably needs attention- which can be accomplished by your, with emery cloth or wet/dry paper in 320 grit and the end of your thumb, rotating your thumb and rotating the gun periodically to get a smooth finish. This type of crown allows a tight ball and patch combination to enter the barrel without harming the ball or cutting the patch. Most barrels, as received from the maker, any maker, need this smoothing to be done as most are merely machine crowned with a lathe and that leaves sharp corners or edges that cut the patch. Cut patches produce built-up fouling and poor accuracy. We use a water based lube for range shooting and a non-rusting oil for hunting. It seems the most accurate water based lube, is spit with some concoctions of watersoluble oil and water worked well too. It's all called experimentation.
Here is a .50 so crowned.
Here is my brother Taylor, loading the combination I mentioned above, into his .50 cal Virginia rifle.