About Reiki initiation (attunement) 

After completed attunement of Reiki,
you will open a connection for the universal life force energy.
You will receive  Reiki energy with your hands without any intention.
Each attunement in a classes will be held 4 times each (3 times each in Reiki 3&4)
It will be completed in about 5 minutes each.
During a attunement, all you have to do is sitting the chair and close your eyes silently.

By using Reiki energy in everyday life after the attunement, 
your connection will be more clear and stronger.