Hi - check out this guide to caring for Christmas cacti: https://www.almanac.com/plant/christmas-cactus
Here's another great guide Faye
Simply put leave it alone,water when top of soil is dry.They do not like constant shifting,the buds fall off.
If it is blooming, water so that it does not dry out. If there is a hole in the bottom of the pot, give the plant a good soaking, let drain into a sink or other container and then place it back on its saucer until the next time. You can add a bit of Schultz plant fertilizer to the water when watering. If not blooming, water sparingly until the buds show up.