Hey dude,
good to see a couple of purchases, hope you have fun!
I wouldn't worry too much about the choice of BBs, these are all about fun. They aren't paper punching target pistols and at 10 metres your into beer can shooting accuracy. However, there is a thread about the H&N lead bb which might be worth reading.
I don't think they will aid much in terms of accuracy (thought they are likely to be heavier so should fly straighter) but they will not ricochet like steel shot does.
It easy to pick up from handling it but once you have shot the 1911 you will certainly understand my enthusiasm for it!