That looks like a pretty difficult task, as it is not easy to relate Bitcoin to "tangible" things mostly shown in museums. But it may work. Good luck
Take advantage from the fact that you'll have more space dedicated to Bitcoin than most people - most see explanations and infographics on small screens, with luck on a big TV. I would propose a big screen covering one whole wall, where you could show difficult-to-grasp ideas in animations, like the way mining and the blockchain work, and even things like an 51% attack (where one chain replaces another). You could even include a kind of blockchain game, to show the general principles of Proof of Work. That could be realized as a card game which you could sell at the museum.
And yes, a big (and expanding) timeline, photos of the first Pizza bought with Bitcoin, Casascius Coins, photos of a mining farm in China, etc.