Question about Types

you can't make fileds Private or Public

The Private and Public keywords are merely there for making sections of code accessible outside the current sourcefile or not.

Type Foo
  Field Foobar:String

  Method New()
    Foobar = MyEnum.First
  End Method
End Field

'// everything below this keyword is only accessible from within this sourcefile.
'// Calling it outside this sourcefile will generate an error.
Private 
Type MyEnum
   Const  First:String = "1", ..
          Second:String = "2" 
End Type

So the above will only work if Type Foo is in the same file as MyEnum.
The Public keyword is applied by default. So if you dont use these keywords, everything is Public automaticly.