We recommend the following useful text functions if you are looking to take sheets data and build usernames or passwords:
=CONCATENATE(string1, string2) or the "&" argument to glue together string values.
=LEFT(string, N) to pull the leftmost N characters from a string.
=RIGHT(string, N) to pull the rightmost N characters from a string.
=LOWER(string) to drop a string into lowercase
=RANDBETWEEN(lowNumber, highNumber) to generate a random number between two numbers
Example:
Let the values in row 2, column D be "First name" (Tyrell), E be "Last name" (Maccombs) and Y be "Student ID" (21043543)...
The formula:
=LOWER(LEFT(D2, 1)&E2&RIGHT(Y2,4)&"@myschool.org"))
...will produce:
tmaccombs3543@myschool.org