Can someone explain to me all about Belgian Congo. Also all the countries involved in this.
I think it would help you a lot to ask a more specific question.
There was an AMA by /r/Matthew_G_Stanard some months ago which could be a starting point for you: https://www.reddit.com/r/AskHistorians/comments/3iaa08/ama_selling_the_congo_and_belgian_imperialism/