Here’s a suggestion for filling in the gaps:

There are two chairs and a desk in this room. There’s a cushion **on** one chair. There’s a bag **by** the other chair. There’s a **lamp** and a **notebook** on the desk. There are books on the **shelf**. There’s a mirror **on** the wall. There are some clothes in the **drawer**. There’s a small **rug** on the floor.