You need a warm greenhouse or conservatory to grow Wax plants successfully. Not surprisingly as these originate in the tropical Far East. The first, Hoya carnosa, was introduced to the UK from Java in 1802 and proved an immediate success. In the next fifty years another two dozen species were collected but none ever challenged the popularity of carnosa.
Very useful for semi shady positions the Wax plant is a twiner and can be run up a trellis. By far most attractive though is using a hanging pot where the plant can be wound in to form a ball. Then when the clusters of flowers are formed these dot the surface. However to be honest there are seldom more than a few clusters open at a time though each has a dozen or more blooms.
This does not matter as although the flowers are not large nor numerous they are exquisite, jewel like. The flowers are also scented, especially in the evening, and perhaps the best virtue is how they will perfume the greenhouse for many weeks on and off through summer and autumn.
I guess if you could get the seed which is not usually available then you could start with that however Hoyas are slow growing so better purchase a choice specimen. Ideally pot up in a turf based loamy compost with added leaf mould and sharp sand as good drainage is essential. Hoyas dislike water-logging even wet compost over winter when their compost needs to nearly dry out.
Other than light feeding with careful regular watering their main care is winding in the twining shoots to form a ball. The plants enjoy a spraying to clean the evergreen leaves of dust. Obviously dead ones can be removed though never cut off the flowers or trim off the dead as those are where the next batch form.
For the collector there’s a half dozen improved varieties of H. Carnosa and another dozen or so similar species available, with over two hundred known.
One note; Hoya flowers exude a sweet nectar which may sometimes drip so hang the plants where this won’t do any harm not over your priceless whatever.