Choose your Amaryllis bulbs carefully. You will find that bulbs that have started to grow while in the store displays are often stressed, and in that first year the flowers will be smaller- if they produce any at all.
You want to pick bulbs that either don’t have, or whose bud tip is barely showing. Make sure that the bulb still feels firm when you touch it as well. I’ve often found bulbs rotting in the store shelves because they’ve been kept in a too warm area.
Many of the bulb kits contain a bag of peat moss, a cheap plastic pot and a small bulb. You might do better trying to find larger bulbs as they often grow and have two stalks instead of one. It’s far better to perhaps purchase loose quality bulbs of a good size and plant them yourself in a good soil mix. I’m sure you’ll appreciate the results.