Tips and advice pls

Ok so I had a question so my 5 month old doesn’t have a sleeping schedule but I want him to have one but I don’t know how to start or how to make one. My baby sleeps very late like 11pm or 12am and I feel like it’s not healthy for his age. He doesn’t take naps that often either but it’s okay I don’t mind I just want him to sleep at night and have a good routine and I don’t know what to do or how to fix it. Please help