What information is passed ?

In part one (I assume you are referring to part 1) we get a little bit of Marlow's past. He is an experienced sea-man but is not prepared for anything like he is going to see in the African Congo. Initially there is a sense of excitement and almost honour about British imperialism bringing "civilization" to the savage world. Upon arriving to the Congo, Marlow sees it as an alien and sad world. It is a world that is being exploited rather than discovered. We also learn the main thrust of the plot. A steamboat id dispatched to find a rouge white employee of the company named Kurtz.