There are quite some shops on board the Disney Dream, each with its own selection.
Mickey’s Main Sail
Here you mostly find toys, plush and collector items like pins and vinylmations.
This is a more upscale store with handbags and other cloths. You can also find tax free items there like alcohol and tabaco.
This is the store with mostly souvernirs of the ship itself. T-shirts, mousepads, magnets, figurines, towels, …
This is a small store on deck that’s not always open, but mostly sells swimwear, swim glasses, sunscreen, …