I am trying to create a function that inserts spaces between the characters of a string argument then return a new string which contains the same characters as the argument,
You can use the split() function to turn the string into an array of single characters, and then the join() function to turn that back into a string where you specify a joining character (specifying space as the joining character):
function insertSpaces(aString) {
return aString.split("").join(" ");
}
(Note that the parameter to split() is the character you want to split on so, e.g., you can use split(",") to break up a comma-separated list, but if you pass an empty string it just splits up every character.)