In American English, “in” the street usually means “in/on the part of the road where cars drive.” Example: “The children are playing in the street. It’s not safe because cars might hit them.”
In contrast, “on the street” can mean the same thing, but it can more broadly refer to things near or along the street. Example: “There are a lot of fancy shops on that street.” “The houses on that street are beautiful.” In American English, we wouldn’t use “in” for this broader meaning.