I want to use whatsapp (talk with a person) without him learning my real number or by using a fake number
is that possible?
there are several guides on the net, but I couldn't find a decent one!
If you don't mind spending a little extra money, it's not all bad to set up a whole new separate internet phone for general use that is only used for special case uses. I have Magic Jack paid for five years for that kind of thing and I tell people it's "outbound only" so it should "never ring".
(And in one weird case, here in NY City USA one of the agencies told me "oh, you bought your cell phone in Massachusetts? Sorry, we can't call you" (?!!) )
Plus just general emergencies and weirdness like "I lost my phone, let's dial it ... Oh! It's under the laundry!!"