What kind of substrate do I need for my red cherry shrimp 10 gallon tank?

when you say substrate I ume you mean the bottom coat.If so your substrate is a filter also helps to keep nitrate out of the water as well.For shrimp I would say sand but having 8 fish as well I would go with gravel to keep fecal matter on the bottom.Slope it thick in the back to less in the front.