Working with strings and numbers two different things in excel. So we have category of text and string functions in excel.
How do you substitute one string with another?? We can do this with SUBSTITUTE formula which is covered in this blog. Similarly to combine different cells data into one we will use CONCATENATE function, to remove unwanted spaces we use TRIM function, to find the number of characters in a cell we use LEN function, to extract number of characters from the left side of the string we have LEFT function, to make the string or text proper sentence we use PROPER function and many more TEXT and String functions are covered in this blog.