In order to make a weaponsmith villager, the first thing you’d need to do is to make a grindstone from two sticks, one stone slab and two oak planks using the crafting table. Take out these things from the chest box and put them in inventory then place them in a crafting table to make a grindstone. Add this grindstone back in inventory.
Now you need to find a village to get to a villager. Place the grindstone next to an unemployed villager. He will become a weaponsmith villager by doing this.