Good enough gun to start out with. If you like it you will move on to something better. If not you shouldn't be out more than 250 bucks (if you bought the bare rifle).
You can shoot pellets or loose powder with this.
With Pellets you can generally get 50 grain and 30 grain pellets - either Pyrodex or 777.
A typical pellet load might be 80 or 100 grains under a Sabot (tons available from all the mfgs with anything from a 240 grain to 300 grain pistol bullet as the ultimate projectile), a Powerbelt or FPB (plus a number of others from other mfg's - a bullet that doesn't go in a sabot, but loads "as is" out of the box) or many of the traditional conicals (great plains bullets, maxi-hunters etc, that are "lubed" before loading.
This has 1:28 twist rifling - it can't shoot round balls (it can, but you would have to really reduce the powder charge making it impractical for hunting) and not all sabot's, solids or conicals will shoot well from it. Every maker has their own idea of "what twist is best", they are all different and as a result there is many bullets out there that will work in rifle A well but not rifle B.
Loose powder (Pyrodex RS or Select or 777 in FF is common) would allow you to "tweak" your charge (think of a handloader with centerfire stuff).
Accuracy is good out to 100 yards - you can probably stretch that with practice and "loose powder" (lots of piddling around, increasing 5 grains at a time, trying different projectiles)
Don't load it to the max (per the manual), stuff something down the tube and expect it to shoot like a center fire rifle - it don't work like that. Start at a lower charge weight and "piddle around" - there is no magic formula with these things.
In terms of glass, think of this as a "shotgun" - you have about the same max range and trajectory. It's never going to be a CF gun, don't fool yourself that it will be - treat it like you are hunting with a shotgun and you will be fine.
And if you are totally unfamiliar with BP guns, the "must clean after every time it is fired" is not a suggestion. If you don't you will have a rusted mess in a month or less - if it goes bang, it gets cleaned that night.
777 is a little less corrosive than other options (and if you believe the ads that say their BP Substitute is non-corrosive maybe they will buy you a new rifle when yours is rusted solid), but it still must be cleaned after it's been shot.
