Thanks all of you for your replies but I would like to find a person to teach some things from begin and I would like to create my own functions to make the communication and not to use existing codes; for instance Arduino. If you know anyone that will be interesting to do this, please send me a pm to give you my email. Thanks!
What exactly do you want to learn? Do you want to write your own stack? Do you want to leverage a stack? Do you want to use an integrated module with an API? Do you want to design a discrete chip solution? do you want to build something with a FCC certified module?
Let me offer a suggestion:
If you are building as a hobby, use a module with an API
if you are building a few hundred per year, use a module with an API
if you are building a few thousand per year, use a module with an API
if you are building a few 10s of thousands per year, consider a packaged stack and a discrete chip solution and pay for FCC compliance (easily $20k for worldwide compliance)
if you are building a few 100k a year or more, then get your chip manf to design it for you