Images shown are just examples of what you can get. It is mix of a lot of species and they are mixed all together so there is no guarantee that you will get exactly what you see but maybe other varieties of Selenicereus .
Selenicereus has amazing flowers that open at night.
Sow in good cactus compost that drains well. Keep at a temperature of 17 - 20C on a windowsill. Water thoroughly when soil is dry to the touch. Keep in the seed tray for as long as possible and pot up when large enough to handle.