You could use the separate function from the tidyr package.
library(tidyr)
DF <- data.frame(Address = c("250 Maple St.", "5 Spruce", "1563 Main"))
DF
#> Address
#> 1 250 Maple St.
#> 2 5 Spruce
#> 3 1563 Main
DF <- DF |> separate(Address, into = c("Number", "Street"), extra = "merge")
DF
#> Number Street
#> 1 250 Maple St.
#> 2 5 Spruce
#> 3 1563 Main
Created on 2022-06-15 by the reprex package (v2.0.1)