Start, begin or commence
Start
Everyday: speech and messages; fine in most writing too.
The movie starts at six.
Begin
Neutral to slightly formal: stories, essays, instructions.
The story begins in a small village near Mysuru.
Commence
Very formal: official notices and ceremonies.
Examinations will commence on 10 March.
Remember: Start with friends, begin in essays, commence only in notices. Using commence in chat sounds like a circular.