Now I have to agree with Hawg. I shoot both and there are days I just don't want the clean-up hassles associated with BP. I have had no problems with Pyrodex. And in some areas of the country, sellers have ceased to sell BP and Pryodex is all we can get locally. It is a 140 miles for me to get BP.
As you are just starting and not into all that realism. Pyrodex will work fine and it may be all you can get locally.
As for loads, you have been given good advice. One other thing you may consider are wads or lube pills. This is another thing that will stir up a hornets nest. There are those who do not use either. Others that will use cornmeal as a filler. And there are those who swear by Crisco placed liberally over the ball.
You will have to find out what you are comfortable with.