Fernando:
Primero que nada, bienvenido a DNN.
Your question is very valid and typical of people new to DNN even with some experience developing with ASP.Net. I would recommend you to get started with the "Install" package of version 4.9.0. This is a complete, pre-compiled version of DNN with all the functionality to setup either a production installation on a server or a test/development environment in your notebook. This confuses a lot of newbies, but you do not, I repeat, DO NOT need any developer tool to get started with DNN. You do not need the source code of the DNN core either.
Now, if you want to develop your own modules for DNN, I would recommend you to go to Michael Washington's Web site and study his excellent tutorials at this link. Specifically, the ones entitled "Setting-up the Environment". To develop new modules for DNN 4.9 you need either Visual Studio 2005 or higher or VS Express 2005 or higher. Your notebook should work just fine for test and development.
Hope this helps you. By the way, your English is not too bad.
Carlos
(Un Puertorriqueño en Maryland, USA)