struggling to work out how to change the temp and humid setting with buttons

Using google and snippets of other code examples ive managed to get this far but am struggling to find how to change the temp and humid setting with the buttons on my dfrobot lcd keypad shield

//Arduino ReptiTherm project. 


#include <LiquidCrystal.h>
#include <DFR_Key.h>
#include "DHT.h"

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

DFR_Key keypad;

// Uncomment whatever type you're using!
//#define DHTTYPE DHT11   // DHT 11 
#define DHTTYPE DHT22   // DHT 22  (AM2302)
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor


  
int sensePin = 11; //Arduino Pin number the sensor plugged into. The schematics that come with the LCD shield are incorrect.
//Pin 2 on the arduino is actually pin 5 on the LCD shield. The headers that plug into the arduino's Digital pins 0 - 7, on the LCD Shield the exact middle pin is pin 2 on the arduino.
//Use your multimeter to test continuity to find the pin you want.
int currentButton = 0; //Current button pressed
int displayTemp = 1; //Keeps track of what screen is currently being displayed. If displatTemp is 1 temp is showing. If 0 Humidity is showing.
int displayHumid = 0;
int setTemp = 30; //Default to set the desired temp
int setHumid = 70; //Defualt to set the desired humidity
int outputPin = 3; //Output pin to the relay to trip the fans

DHT dht(sensePin, DHTTYPE);

void setup() 
{ 

  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("ReptiTherm v0.1"); //prints name
  lcd.setCursor(0, 1);
  delay(3000);
  lcd.print("Initializing...");
  lcd.setCursor(0, 1);
  delay(2000); 
  
  
  pinMode(outputPin, OUTPUT);
  
  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(0, 0);
  
  Serial.begin(9600); 
  
  dht.begin();
}

void loop() {
  
  currentButton = keypad.getKey(); //Read button press
  
  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  float t = dht.readTemperature();

float temp = 0; //Convert *C to *F.

if (displayTemp == 1) //Shows temp screen upon first boot
{
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("TEMP       ");
    lcd.print(temp);
    lcd.print("  ");
    lcd.print((char)223); // degree symbol
    lcd.print("C");
    lcd.setCursor(0,1);
    lcd.print("SET TEMP   ");
    lcd.print(setTemp);
    lcd.print(" ");
    lcd.print((char)223);
    lcd.print("C");
    displayHumid = 0;
    
}
else{
  lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("HUMIDITY    ");
    lcd.print(int(h));
    lcd.print(" %");
    lcd.setCursor(0,1);
    lcd.print("SET HUMID   ");
    lcd.print(setHumid);
    lcd.print(" %");
    displayHumid = 1;
}

// Reads which buttons are pressed. 
// No button = 0
// Select button = 1
// Left button = 2
// Up Button = 3
// Down Button = 4
// Right Button = 5

if (currentButton == 5 && displayTemp == 1)
{
   displayTemp = 0; //Turns display temp off so it will show humidity after pressing right button
}

// The following code toggles the screen when the corresponding button is pressed.
// Also sets the screens to wrap around the display. 
// So if you hit right button once it will show humidity and if you hit right button again it will show temp.

if (currentButton == 5 && displayHumid == 1)
{  
  displayTemp = 1;
}

if (currentButton == 2 && displayTemp == 1)
{
   displayTemp = 0;
}

if (currentButton == 2 && displayHumid == 1)
{
  
  displayTemp = 1;
}

if (currentButton == 3 && displayTemp == 1) //When up button is pressed and the temp screen is showing, increment the set temp
{
   ++setTemp;
}

if (currentButton == 4 && displayTemp == 1) //When down button is pressed with the temp screen showing, decrement set temp
{
   --setTemp;
}

if (currentButton == 3 && displayTemp == 0) //When up button is pressed and the humidity screen is showing, inc the set humidity
{
  ++setHumid;
}

if (currentButton == 4 && displayTemp == 0) //When down button is pressed and humidity screen is showing, dec the set humidity
{
  --setHumid;
}

if(temp >= setTemp) //Trip relay if temp is exceeded
{
  Serial.print(temp);
  digitalWrite(outputPin, HIGH); 
}
else
   {
    digitalWrite(outputPin, LOW);
   }



if (h >= setHumid && digitalRead(outputPin) == LOW) //If humidity is exceeded and fan is not on due to temp exceeded, turn fan on.
{
  digitalWrite(outputPin, HIGH);
}


}
if (currentButton == 5 && displayTemp == 1)
{
   displayTemp = 0; //Turns display temp off so it will show humidity after pressing right button
}

// The following code toggles the screen when the corresponding button is pressed.
// Also sets the screens to wrap around the display. 
// So if you hit right button once it will show humidity and if you hit right button again it will show temp.

if (currentButton == 5 && displayHumid == 1)
{  
  displayTemp = 1;
}

It looks like you want to display temperature OR humidity. One variable would be enough to determine which to display. If you are going to have two, you must make sure to set BOTH at the same time.

  Serial.print(temp);

Printing anonymous values wastes everyone's time.

if (h >= setHumid && digitalRead(outputPin) == LOW) //If humidity is exceeded and fan is not on due to temp exceeded, turn fan on.

Why would you need to read the state of the output pin, after you set it? Remember what you set it to.

Now, the biggest problem with that code is that it does something, and you want it to do something. I think it's safe to assume that if the two somethings were the SAME thing you would not have felt it necessary to post the code. Since you did, I think it's safe to assume that the two somethings are not the same thing.

What either one of them is, though, is a complete mystery.

This is my first proper project and like I said I've used snippets of example code . If I had a bigger screen I would like to show humidity and tempriture at the same time and then maybe have a menu to setup the limits do you know of any projects that I might be able to use as a reference.

Thanks