I leave a light on with angel fry for the first 2-3 weeks. This keeps them from settling on the bottom, where the majority of the bacteria accumilate. Bare bottom tanks are best for cleanliness, wipe the bottom with a paper towel daily before water changes. Fry are delicate, trickle the water in for water changes, I use a gallon jug with a 1/8" hole punched in it.
As far as food, a finely crushed quality flake, along with the bbs should be fine. It's tough to determine how much to feed without overfeeding, especially with fry. I cheat, & put a small cory in fry tanks to take care of any excess.