So when I close my eyes at night I have no feeling that I dreamed, its like I close my eyes and just open them during the night when I need to change my sleeping position.

I wanna know how to dream and how to control them.

I have no idea how dreams are classified, are dreams the scenarios I construct whenever I want to ? ( like when I imagine a bowl of ice cream in a desert )
Or are dreams something that starts on its own ?

In the past I have experienced scenarios that my brain generates while I was asleep, it had quite a realistic feeling, but I have never been able to reconstruct this in any way.