How to lose weight in a week?

I want to lose like 20 -25 pounds. But obviously that’s not going to happen in a week. But I want to lose some weight fast! So how do I get started? I don’t want any pills or shakes or those little meals. So if you know a way to lose weight with out all those things than please share it with me! thanks!
-Julia
Or is there shakes i can buy at my local stores?