Im working on $2$D platfomer in UNity using C#$.$ I created a levelmanager script to load each level and save player progress. However, im now trying to add a checkpoint system, with the last cehckpoint activated also saved. Heres my levelmanager code so far:

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using UnityEngine.UI;

using UnityEngine.SceneManagement;

public class LevelManager : MonoBehaviour

$\{$

$//$declare levelsUnlocked

int levelsUnlocked;

$//$declare checkpointsUnlocked

int checkpointsUnlocked;

$//$holds the transform value

public Vector$3$ lastCheckPointActivated;

$//$declare boolean levelWon and set to false

bool levelWon $=$ false;

$//$need fixing a placeholder value

int playerStartPos $=0$;

$//$levelWon function

public void levelIsWon$()$

$\{$

$//$set levelWon to true

levelWon $=$ true;

$\}$

$//$start function

void Start$()$

$\{$

$//$sets levelsUnlocked to integer stored in Player preferences. If no int is stored the value is $1$

levelsUnlocked $=$ PlayerPrefs.GetInt$("$levelsUnlocked$",1)$;

$//$check last checkpoint unlocked.If no integer is store set equal to $0$

checkpointsUnlocked $=$ PlayerPrefs.GetInt$("$checkpointsUnlocked$",0)$;

$//$calls levelLoad function to load the level indicated by levelsUnlocked

levelLoad$()$;

checkpointLoad$()$;

$\}$

$//$loadLevel function

public void loadLevel$($int levelNum$)$

$\{$

$//$load the level

SceneManager.LoadScene$($levelNum$)$;

$\}$

$//$update function

void Update$()$

$\{$

$//$if levelWon equals true

if $($levelWon $==$ true$)$

$\{$

checkpointsUnlocked $=0$;

$//$and if levelsUnlocked is less than $9$

if $($levelsUnlocked $<9)$

$\{$

$//$increment levelsUnlocked by one

levelsUnlocked$++$;

$//$save new value to levelsUnlocked

PlayerPrefs.SetInt$("$levelsUnlocked$",$ levelsUnlocked$)$;

$//$set checkpoint to $0$

PlayerPrefs.GetInt$("$checkpointsUnlocked$",0)$;

$\}$

else if $($levelsUnlocked $>9)$

$\{$

$//$load the credits scene

SceneManager.LoadScene$(10)$;

$\}$

$//$sets levelWon back to false

levelWon $=$ false;

$\}$

$\}$

$//$level load function

void levelLoad$()$

$\{$

$//$if levelsUnlocked is less than or equal to $1$

if $($levelsUnlocked $>=1)$

$\{$

$//$load level $1$

SceneManager.LoadScene$(1)$;

$\}$

$//$else if levelsUnlocked equals $2$

else if $($levelsUnlocked $==2)$

$\{$

$//$load level $2$

SceneManager.LoadScene$(2)$;

$\}$

$//$else if levelsUnlocked equals $3$

else if $($levelsUnlocked $==3)$

$\{$

$//$load level three

SceneManager.LoadScene$(3)$;

$\}$

$//$else if levelsUnlcoked equals $4$

else if $($levelsUnlocked $==4)$

$\{$

$//$load level $4$

SceneManager.LoadScene$(4)$;

$\}$

$//$else if levelsUnlocked equals $5$

else if $($levelsUnlocked $==5)$

$\{$

$//$load level five

SceneManager.LoadScene$(5)$;

$\}$

$//$else if levelsUnlocked equals $6$

else if $($levelsUnlocked $==6)$

$\{$

$//$load level six

SceneManager.LoadScene$(6)$;

$\}$

$//$else if levelsUnlocked equals $7$

else if $($levelsUnlocked $==7)$

$\{$

$//$load level seven

SceneManager.LoadScene$(7)$;

$\}$

$//$else if levelsUnlocked equals $8$

else if $($levelsUnlocked $==8)$

$\{$

$//$load level eight

SceneManager.LoadScene$(8)$;

$\}$

$//$else if levelsUnlocked equals $9$

else if $($levelsUnlocked $==9)$

$\{$

$//$load level nine

SceneManager.LoadScene$(9)$;

$\}$

$\}$

void checkpointLoad$()$

$\{$

$//$if checkpointsUnlocked equals $0$

if $($checkpointsUnlocked $==0)$

$\{$

$//$player starts at beginning of level

$//$ playerStartPos $==(0)$;

$\}$

$//$if checkpointsUnlocked equals $1$

else if $($checkpointsUnlocked $==01)$

$\{$

$//$player starts at checkpoint$1$

$\}$

$//$if checkpointsUnlocked equals $2$

else if $($checkpointsUnlocked $==02)$

$\{$

$//$player position is at checkpoint $2$

$\}$

$//$else if checkpointsUnlocked equals $3$

else if $($checkpointsUnlocked $==03)$

$\{$

$//$player position is at checkpoint $3$

$\}$

$//$else if checkpointsUnlocked equals $4$

else if $($checkpointsUnlocked $==04)$

$\{$

$//$player pos is at checkpoint$4$

Here is my checkpoint code thus far:

public class Checkpoint : MonoBehaviour

$\{$

private LevelManager lm;

void onTriggerEnter$2$D$($Collider$2$D other$)$

$\{$

$//$if player collides w

Im a litle rusty so any guidance would be appreciated