the list of weapons and their game stats (think damage, speed, etc) are on module_items.py -> item_kinds1.txt. However that doesnt include the sounds, animations, triggers (special code), tableaus and 3D info related to them. So you will need to check a lot more stuff if you are porting items from another mod.
Also remember if your mod is PUBLIC you will need to get permission for the stuff you are using.
instead of trying to blind copy stuff from a mod, you should instead start on a easy task. Find a tutorial on how to add a item and follow those instructions. Then a tutorial on how to create a new soldier troop. Etc. Learn the basics before you try the hard stuff.