Yes, you can grow an amaryllis in a pot. They won't bloom unless crowded, so you need to use quite a small pot for the bulb. A pot 4 to 6 inches in diameter is about right, depending on the size of the bulb you bought.
When you plant the bulb, place some kind of stake beside it to support the stem as it grows. The flowers are large, making the plant top heavy. Sometimes, the stem cannot support the flowers, which is why the stake is important.
The stem will sprout first, followed by the leaves. The plant needs bright light and soil that is consistently moist, but not soggy.
You may want to fertilize the plant every couple of weeks. I like to use a liquid fertilizer mixed at half the strength described on the label. Whatever kind you choose, it should be dissolved it in water before being applied.
Those are the basic instructions. You can find more detail at this site:
https://lancaster.unl.edu/hort/nebline/amaryllis.shtml
Enjoy your amaryllis! They are traditionally used as decorations during the Christmas season, and I always buy one or two to brighten my home through the gray cold days.
