Final answer:
Harry Potter's bedroom may have had Quidditch posters and possibly his Nimbus 2000 broomstick, while a troll foot umbrella stand would be unlikely, and Bertie Bott's Every Flavor Beans could have been present as a sweet.
Step-by-step explanation:
In the summer of 1994, the floor of Harry Potter's bedroom was not specifically described in great detail regarding these items. However, if we reference Harry's possessions and the general setting from J.K. Rowling's books, we can infer a likely scenario.
Harry certainly had Quidditch posters on his wall, as he was a fan of the sport and a player for his house team at Hogwarts. He might have had his Nimbus 2000 broomstick, as it was his primary broom for Quidditch until it was destroyed during his third year.
It is unlikely the floor would have a troll foot umbrella stand because such an object would be out of place in Harry's modest bedroom. Bertie Bott's Every Flavor Beans could be a small item on his floor since they are a popular wizarding sweet and Harry might have had some in his room.