type
  TMyClass = class
  private
    FSomeField: Integer; // by convention, fields are usually private and exposed as properties
  public
    constructor Create;
    begin
       FSomeField := -1;
    end;
    procedure SomeMethod;
    property SomeField: Integer read FSomeField write FSomeField;
  end;

procedure TMyClass.SomeMethod;
begin
  // do something
end;


var lMyClass: TMyClass;

lMyClass := new TMyClass; // can also use TMyClass.Create

lMyClass.SomeField := 99;
lMyClass.SomeMethod;