1.
If you ~ by doing something, you do it as the first part of an activity.
She started off by accusing him of blackmail but he more or less ignored her...
Joe Loss started off playing piano background music for silent films in the 1920s.
PHRASAL VERB: V P by -ing, V P -ing
2.
To start someone off means to cause them to begin doing something.
Her mother started her off acting in children’s theatre.
PHRASAL VERB: V n P
3.
To start something off means to cause it to begin.
Best results are obtained by starting the plants off in a warm greenhouse.
PHRASAL VERB: V n P
4.
see start 4