Complex sentence: First, it offers recruits the chance to get accustomed to their weapons so that they will know how to properly operate them; secondly, this provides soldiers with an opportunity to fire live ammunition without having to worry about an actual enemy returning fire.
Split into simpler sentences: First, it offers recruits the chance to get accustomed to their weapons so that they will know how to properly operate them. Secondly, this provides soldiers with an opportunity to fire live ammunition without having to worry about an actual enemy returning fire.