How does spacecraft navigate in space if it's destination is one of the Lagrange points?

Hello,

Sorry if this question may sound repetitive or obvious..

If a spacecraft were to visit a planet, i know it navigates using the precise math of where that planet will be on a particular day and it’s current and future locations in orbit.

But if the spacecraft is visiting one of the Lagrange point (L2 for example), how will it know that it has reached it’s destination?, since the place is empty, there’s no map aside from it’s 1.5 million kilometers away from earth.

Please explain.. or point me to webpage which explains the same.

I appreciate the answers..

Regards!