I can't use execute annonymous to get the debug because when I try to execute the code I get this error: "line 13, column 11: unexpected token: 'class'". This is despite the fact that it lets me save the controller in my browser with no errors given.

Controller:

public with sharing class TeacherlistatSchoolX2{

    public List<pagemetrics> pm {get;set;}
    public Id thisContactId {get;set;}

    
    //Initiate in constructor
    public TeacherlistatSchoolX2 () {
    getMetriclist();
    }
    
    //new Class to hold metrics
    public class pagemetrics {
    public integer class_grade {get;set;}
    public integer A {get;set;}
    public integer of_scheduled_time_online {get;set;}
    public decimal hours_online {get;set;}
    
    public pagemetrics (integer CG, integer perA, integer TO, decimal HO) {
    class_grade = CG;
    A = perA;
    of_scheduled_time_online = TO;
    hours_online = HO;
    
    }
    }
    
    public List<Teacher_Implementation__c> Teacherlist;
    public List<Class_Implementation__c> Classlist;
    
    public List<Teacher_Implementation__c> getTeacherlist() {
        if (Teacherlist == null) {
            Teacherlist = 
            [SELECT Id, Name, School_Implementation__r.Name, School_Implementation__r.Principal_Name__c, 
            School_Implementation__r.Id FROM Teacher_Implementation__c 
            WHERE School_Implementation__r.Principal_Name__c = :thiscontactid];
        }
        return Teacherlist;
    }
    
    public List<Class_Implementation__c> getClasslist() {
        if (Classlist == null) {
            Classlist = [SELECT Id, Name, Teacher_Implementation__r.Name, 
            Teacher_Implementation__r.Id, Grade__c
            FROM Class_Implementation__c 
            WHERE Teacher_Implementation__r.id IN :getTeacherlist()];
        }
        return Classlist;
    }
 
 
//Generate metrics
public void getMetriclist(){ 

//Create new list to hold results based on new class
pm = new List<pagemetrics>();

    AggregateResult[] Metriclist =
        [SELECT MIN(date_difference__c), MIN(Class_Implementation__r.Id), AVG(A__c) perA, Start_Date__c, MIN(class_grade__c) CG
        FROM Class_Metric__c
        WHERE (date_difference__c >= 0) AND (Class_Implementation__r.Id IN :getClasslist())
        GROUP BY Start_Date__c];
    
    //Loop through results and add each result to new class so we can display
    for (AggregateResult ar : Metriclist) {
    pm.add(new pagemetrics ((Integer)ar.get('CG'), (Integer)ar.get('perA'), (Integer)ar.get('TO'), (Decimal)ar.get('HO')));
    }

    }
    
}

Component:

<apex:component controller="TeacherlistatSchoolX2" access="global">
  <apex:attribute name="ContactID" description="This is the contact Id." type="Id" assignTo="{!thisContactId}"/>

[ %A ] - [ % of scheduled time online ] - [ Hours Online ]
<apex:repeat var="cx" value="{!pm}">
[ {!cx.Class_Grade} ] [{!cx.A}]
</apex:repeat>

</apex:component>

Email Template:

<messaging:emailTemplate recipientType="Contact"
    relatedToType="School_Implementation__c"
    subject="Update on your teacher implementations" 
    replyTo="trevor.gill@reasoningmind.org">
       
<messaging:plainTextEmailBody >
Dear {!recipient.salutation} {!recipient.lastname},

<c:CL_controller ContactID="{!recipient.Id}"/>

</messaging:plainTextEmailBody>   
</messaging:emailTemplate>