You have chosen to become a weaponist? Of course you have why else would you be on this page. What's more fun than taunting others out of their releases anyways right? No seriously it annoying on the other end. But let's get to the nitty gritty.
Upon reaching level 20 you are now eligible to become a weaponist. First you must travel to the east entrance to what is sometimes referred to as Hollow Swamp or Hollow Hell. Do not go inside though. Ururu is to the right of the house above the entrance. When you speak to her like all the class Npcs you must do a quest for her to become a weaponist. You need to kill 10 weak hollows. Afterwards you return to Ururu and you will become a weaponist. Congrats. Here are the techniques and info about the weapons.
Techniques-
Taunt: Learned at level 45
Golden Kanon Ball: Learned at level 75
Flashstep: Learned at level 135
Rage: Learned at level 150 (Rage increases damage output of weapons and changes the abilities situated with the weapons)
Weapons-
Bat: Strength
Machine Gun: Reiatsu/Reiryoku
Soccerball: (Bugged, do not use)
Cane: Strength/Reiatsu
Katana: Strength/Reiatsu
Gloves: Strength/Defense