Unreal Engine 4 c++ additions

I have a premade UE4 Project in c++ that needs to have several things added to it. First I need a simple AI re-written to make sure it attacks certain objects before switching to attacking the player, second I need to have the option to switch to bow (or just shooting the projectile mode) where a projectile can be shot from the player and third what I need is a sound system within the game, including background sound, players footsteps and sword swing/bow shoot sound.