sink or swim idiom
自己去闯，成败全凭自己
If you are left to sink or swim, you are given no help so that you succeed or fail completely by your own efforts.
My employer gave me no help when I started my new job - I was just left to sink or swim. 开始新工作时，我的老板没有为我提供任何帮助——全凭我自己打拼。