Vandas come in a hanging wire, you can do either leave it hanging or cut the wire and put it in and if you put it in a pot they are happiest when the roots are outside the pot as they have a good draining system,
So for the Vandas you can use big lager bark and larger pots will be the best, larger barks cause their roots are bigger ( if you have other plants with smaller roots use smaller bark )
The little bag of slow-release fertilizer called Nutricote and it’s good for one year. Every time you water the plant or it gets rain on it releases nutrients.
Care for the Vanda Try to place the plant somewhere in bright filtered light not too cold, and water at least twice a week once a day if you can, and water the roots too,