the world is someone's oyster idiom
（某人）可以随心所欲，（某人）可以为所欲为
If the world is your oyster, you can do what you want or go where you want.
You're young and healthy and you have no commitments - the world is your oyster. 你年轻、健康，并且没有什么负担——可以随心所欲地做你想做的事。