cs(6,13): error CS1520: Class, struct, or interface method must have a return type

Hey guys, I've been sitting like an idiot for the last 45 minutes and I've not been able to get this 'return type'. Could someone help? If I set the private GetUpdate() to private void GetUpdate() then the mouseposition and moveSpeed starts to have a recognition problem. Unity presents "error CS0103: The name `mousePosition' does not exist in the current context" and "error CS0103: The name `moveSpeed' does not exist in the current context".
I'm really confused and I'm new to C# and Unity. I've only managed to copy the code and put them where I need it to be (That's allowed right, as long as it's open source and all?) - is it unethical to copy paste other people's code (If open source) and use it in my own game if I don't know how to program and C#? Do I have to accredit them always? That's a side question, but I need this thing fixed really badly! Thanks in advance.
This is the code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class CharacterMovement : MonoBehaviour {
6.     private GetUpdate()
7.     {
8.        if  (Input.GetMouseButton(1))
9.         {
10.             mousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
11.             Vector2 tmpDir = mousePosition - transform.position;
12.             transform.position = Vector2.Lerp(transform.position, mousePosition, moveSpeed * 1f / tmpDir.magnitude * Time.deltaTime);
13.         }    
14.     }
15. }
16.  

 

You aren't going to get anywhere coding until you make an effort to learn. Download Visual Studio and start doing some C# tutorials or use the Learn section of the Unity Website.

 

Yeah, I've just realized. But sadly, I dumbly had said that I was going to make a Unity game to my school and I'm like 40% done (If I will say that 60% is scripting) as I got the models and maps in place. I'll try to learn whenever I can but is there anything I can do now? Like I have a really primal understanding of the language but I know a bit of another language with a similar format (CSS). So if you'd prefer not to say so I could try to learn it myself, I understand and thank you, but is there anything that I have to add (Like how do I declare variables)?

 

You might want to pick up Playmaker then.

 

Oh, thanks a lot. I was kinda familiar with Scratch so I think this will help

 

but other than that, how could I fix the code I presented initially? It's having an issue identifying certain variables and I'm not sure on how do I define/declare the variables of the code presented.

 

Well, it seems pretty hard since the script is not loading right now (Btw I had managed to declare the variables lol. took me a while to learn). Do you know how to fix this warning? :
The referenced script (Character Movement (Whale)) on this Behaviour is missing!
? I freaked out when it wasn't working then I saw this

 

Never mind, I just realized that was impossibly hard code for a newb like me. Found out how to do WASD instead, finally, I can move my character!