how can one create dynamic textboxes from vb.net code it self ?

the controls are classes you can declare one the same as any class, Dim MyTextBox As New TextBox

In order to be useful it is necessary for dynamically created controls to be added to the form (or a container in the form). Typically you also want to add event handlers. There are examples of how to create controls at runtime, attach event handlers, etc. in the code snippets section. one example is here.