In this disseration we explore the structure and construction of certain quantum many-body states, as well as operator dynamics in quantum many-body systems. First, we detail the implementation of a new tensor network ansatz for many-body ground states based on adiabatically evolving a state to repeatedly double in size. Next, we extend the notion of `strong zero modes, ' edge-localized operators stable at infinite temperature, to operators localized to boundaries between systems. We then discuss efforts to numerically characterize scrambling, a strong form of thermalization, in the Sachdev--Ye--Kitaev model. Finally, we show that a states with large momentum splittings can be created via symmetric Bloch oscillations in two optical lattices being accelerated in opposite directions.