I don't know how to play a sound and spawn particles.

What exactly do you not understand?

World#playSound takes in a player that "initiated" the sound aka the one to not play the sound to on the server and the one to play the sound to on the client, the position of the sound, the sound itself(you can find all sounds in the game at SoundEvents class), the category(you can find all categories in SoundCategory class), the volume and the pitch.

World#spawnParticle takes in a particle type to spawn(you can find all particles in the EnumParticleTypes class), the X, Y and Z position of the particle, the X, Y and Z motion of the particle and optional additional arguments for the particle(for example ITEM_CRACK takes an ID and the metadata of the item). Most particles do not have additional arguments.