Having some crazy errors, First time with C# Trying to mess with unity

namespace Namespace;

[Attribute]
public class Class
{
    public string PublicField;
    private bool _privateField;    

    public int PublicProperty { get; set; }

    public Class() {} // Constructor

    public void Method(int parameter)
    {
        var localVariable = parameter; 

        int LocalMethod(string param) { return 3; }
    } 
}

namespace Namespace;

[Attribute]
public class Class
{
    public string PublicField;
    private bool _privateField;    

    public int PublicProperty { get; set; }

    public Class() {} // Constructor

    public void Method(int parameter)
    {
        var localVariable = parameter; 

        int LocalMethod(string param) { return 3; }
    } 
}

Visual Studio        CTRL  + K     + D
Rider / Resharper    CTRL  + ALT   + L
Visual Studio Code   SHIFT + ALT   + F

Visual Studio        CTRL  + K     + D
Rider / Resharper    CTRL  + ALT   + L
Visual Studio Code   SHIFT + ALT   + F