First, Welcome!
Before jumping to set-up, here are some concepts that should help you make sense of the information that you find online.
You have chosen an orchid that has needs that are very different from most orchids. Where most of the orchids that you'll read about are epiphytes (grow on trees in nature), the "egret orchid" - Pecteilis radiata (alternate name Habenaria radiata) - is a terrestrial, growing in the ground. So when you do your research, you can look it up under the scientific name and you will likely find more information. I will give some fairly general advice since this particular one doesn't grow well for me, I can't give it the cold winter that it needs. (From your zone, that's not going to be a problem for you). I do grow warmer-growing Habenaria (closely related genus). All of these are dormant in the winter. So you will be getting a tuber, the ideal time to ship these. The mix I would use is about 2/3 inorganic (such as pumice), the balance a well-drained soil such as cactus mix. (The vendor may have a different mix for this one, follow their advice). Plant the tuber so the top is about 1/2 inch below the soil mix. (the top of the tuber has a little "nubbin") If you're not sure, you can put it on its side and the plant will figure out which way is up when it sprouts, You can dampen the mix a bit, but it should stay fairly dry until spring (not bone dry) Around March or April, start watering lightly. When you see the little green shoot, you can increase the watering. It blooms in the summer, and after blooming the leaves die back to start another cycle. Also note what I said about temperature... this needs to be cold in winter. (probably needs protection from hard frost though, follow the vendor's advice) It comes from the mountains in Japan and China. This is not a tropical orchid!
I found this article, which appears to have a lot of good information:
HOW TO GROW THE WHITE EGRET FLOWER - Pecteilis radiata |The Garden of Eaden
This is totally different from the "standard" orchids (tropical, epiphytic), which need a very open mix (bark, spahgnum, LECA, etc), no soil. Mounting works for epiphytic orchids, since they naturally grow on trees. So good that you have asked, the one you are getting is a completely different group, so that's what makes it all very confusing and contradictory, (The classification of a flower as "an orchid" is based on the "physiology" of the flower, and they come from elevations from sea level to above tree line, from every continent except Antarctica. Of course, with these extremely different habitats, they have very different needs. The majority of the commonly-avaiiable ones are tropical in origin. But the temperate zone terrestrials are fascinating, and fun to grow!)