strike out on (one's) own

Translations
начать самостоятельную жизнь
After college, she decided to strike out on her own and start her own business.
После колледжа она решила начать самостоятельную жизнь и открыть свой бизнес.
Definitions
To begin to do something independently, especially to leave a group or organization in order to pursue one's own goals or start a new venture.