There is a brief overview of weapon stats Here. LOS offers free rotation weapons that change regularly and are great to give you a feel for all the different weapons in the game while also saving you the need to spend game credits, which I would suggest you save up for purchasing permanent weapons. Be patient with the game and in a month or so or semi regular playing you will have unlocked all the weapons in the game and own at least one perm weapon. Weapons in line of sight can all be unlocked with in game currency and also have a level requirement.
