How to do a stationary lunge correctly

Can someone please tell me how to do a stationary lunge correctly? Once upon a time a knew, but now I don’t.

I know the proper form / stance. What I DON’T know, is which leg I am supposed to be pushing off of / working. Like is one supposed to work more than the other or they work together?

If my left leg is in front, right leg behind, is the right leg just a stabilizer and my front / left should be doing most of the work?

I know this sounds so stupid but I’m frustrated I can’t remember such a simple exercise.