when and how to stop feeding on demand?

Abbie
And starting a schedule!
My LO is 4 weeks old today! She eats and sleeps completely when she wants to. I have no specific time I put her down for the night, it could be anywhere between 8,9,10,11 or even 12pm depending on when she ate. She goes 2-2.5 hours And is pretty good at going back to sleep in the night ever as day time she stays awake! This is normal? I see so many posts of women putting there babies down at a certain time ect