I have had 4 bamboo shrimp and all of them had a spot to eat so very unlikely that they will starve to death. However, best thing to do is have a good current around the tank and they will figure where the current is and where the food will float about. All you need to do is feed your fish and maybe add a little bit more if you want but either way they will catch it in the current or go around on the floor sifting through the gravel. The best thing to do is let the food go in the current and very likely it will get to them.
These will make your tank crystal clear which they really do help cleaning out the bits floating and will give a lot of interest in your tank. They do shed their skin so you may find a shrimp on the floor dead but really it is their dead skin that they had molted.
How big were they at the lfs because normally you find them at around 5cm.