noun
initiation
ih-nish-ee-AY-shun/ɪˌnɪʃiˈeɪʃn/
The first entry into a new undertaking.
Receiving the hiking club's patch marks the new member's initiation into group adventures.

Etymology
Initium joins the ideas of beginning and entrance. The related Latin noun denoted participation in secret rites, connecting initiation both with starting something and with entering a group through admission rites.
In context
you've been accepted you have to go through a three-day initiation in the jungle of of chambury um where you go through various rituals and activities
More examples
- The initiation of the project depends on final approval.
- Her first camping trip is an initiation into outdoor life.
- The club holds an initiation ceremony for new members.
Forms
initiation · initiations
initiate verb — To begin something or introduce someone.
Similar words
- introduction
- Emphasizes first exposure to an activity or subject.
- beginning
- Names the start itself, without implying a formal introduction.
- launch
- Usually emphasizes the planned start of a project or venture.