Newly hatched brine shrimp is a good first food. You need to feed them out within 2 hours of hatching so they still have a nutritious yolk sac. After that you can keep some of the hatched brine until they can feed, about 24 hours after hatching, and enrich them for feeding later on. I usually had at least 4-6 broods going at a time so I had 3 hatchers going all the time and staggered them so I would have fresh batches all day.
I did between 3-5 feedings and water changes a day and broke down the fish bowls and sterilized everything every 5 days. I always had back up bowls ready to go and used only natural seawater so all I had to do was be sure the new water was the right temp and transfer the fry to a new bowl set up. After a week or two I started to add cyclopeze and when I could see the red bellies I would increase the frozen food and add chopped mysis as they grew. Then it was straight frozen mysis as a staple with other live critters on occasion.
Commercial growers came up with much better methods and grew higher percentages of the fry to adulthood but this was my method between 2003-08.
Nothing is more rewarding in the hobby then seeing your own captive bred fishes grow up to be beautiful and healthy adults IMHO.
Click on the pic above with the yellow male seahorse and his mate with the huge cirri behind him. These were the best of the best of my 6 generations.