Repition structures?

[Katididit]

Hi, thank you for looking. I am trying to make it so that when a name is entered, a service code nees to be entered either T or S for teacher or student. The first person entered must be a teacher if not it needs to be instructed that a teacher needs to come first. When someone with a service code of the teacher is entered, the program will ask for a room or class number. This will be used to verify that each of the following students entered are being entered in the correct class. The program will also ask how many assignment grades each student in this class will have. Then the program should accept student names and be followed with a service code of S and the class number is entered and verified. That is when it should loop to request and talls the students grades and then the assignment grades will be averages to find the final average of that students grade.
Upon the entry of a new teacher name and service code the program will display the class number and verify that the user is done entering students for the previous class. If the user says no then the teacher name just entered is discarded. If the user says yes, the program will print the previous teacher and class number followed by the corresponding class list, letter grades and overall class average. Then, using the teacher name just entered, it will request a new class code and start a new class list. For any input, if the service code is not a valid code, the input is discarded and the user must be notified of the valid codes and asked to reenter the data. The user should be able to enter the service code in either lower or upper case.
Whew long winded but I think I covered it all. Thank you!