To breed Neons, you'll need very soft, like almost zero hardness, and acidic water, like pH 5.5. This water is very unstable and subject to wild pH fluctuations. In harder water, the eggs simply won't hatch.
You'll need to keep the males and females apart for a few weeks, and condition well with high quality foods. Put a pair in the breeding tank, female first the day before, male at lights out the day before spawning. They'll usually spawn at first light. As soon as they stop laying, both must be removed or they will eat the eggs. They scatter over feathery plant thickets or spawning mops.
I would never recommend Neons as a first egglayer species to breed. They are difficult to hatch and difficult to raise. Zebras or Rosy Barbs are so much easier.