The phrase “You know your way around” means: You're familiar with a place, system, or topic—you know how things work. Other ways to say it: You seem to know what you’re doing. You’ve clearly done this before. You’re pretty experienced with this. You know the ropes. (idiom) You’ve got this down. (informal) You’re no stranger to this.

You can say something like 'you know it inside and out', 'you've got a good handle on it' or 'you're familiar with it'