The eggs will hatch in 3-4 days depending on water temp. When they hatch you will see little tails wiggling(wiggler stage) then in 3-4 more days(free swimming) the fry will be swimming around. You can separate fry and parents at any time. Do not feed the fry until the next day after going free swimming. This allows them to use up their egg sac, The fry can eat freshly hatched baby brine shrimp. With a magnifying glass you can see their tummys are orange if their eating.
Being the first time your angels have spawned they may eat their eggs, or the eggs may all turn white(not fertilized). If they are truly a pair it may take some practice to get it right.
Hang in there and let us know how it goes

carol