C# var types

I have just decided to switch from javascript to c# but I keep getting stuck in situations when c# wants to know what type of variable i am using. For example :

     forward= transform.forward;

So Its obvious that c# want’s to know what type of variable forward should be. I tried Vector3 but it sorta messed up my code. Can I have a list of all the variable types that I can do here so I don’t get stuck on these things in the future? It would be greatly appreciated.

Here are some common type you may need:

//Formatting
[Access Modifier] [type] [name];
public GameObject someObject;
public Transform someTransform;
public Vector3 someVector = new Vector3();
public float someFloat = 1f;
public int someInt = 1;
public string someString = "";
public bool someBool = false;
public Camera someCamera;
public [someClassName] someClass = new [someClassName](); //this creates a new instance of a class

It is type transform I think.
Public Transform forward;