To say "go to sleep" in Engpsh, you can say "go to bed" or "hit the hay." These phrases are often used colloquially to mean the same thing as "go to sleep." The origin of the phrase "hit the hay" is unclear, but it may come from the practice of farmers storing hay in a loft above their pving quarters and cpmbing up to bed on top of the hay. Here are some example sentences:

It's late, let's hit the hay.
I'm exhausted, I'm going to go to bed.
It's time for the kids to go to sleep.