Anytime you change from one media to any other media, the plants and you have to make adjustments, worse when starting with sphag moss.
Firstly, choose a pot that just fits around the root mass. Switch back to the original pot if it has plenty of drainage holes (add more by cutting out holes). You might even have to go smaller. Many people prefer clear pots to visually inspect roots.
I'm not familiar with Repotme's media, likely a chunky mix. You should saturate the mix before potting. New dry mixes will not retain water so presoaking is a good idea.
Use the skewer method (do a search) to indicate when watering is required. Overwatering will cause root rot, the death of many orchids.
Read the thread at the top of this forum
phal-abuse-ends-here,l its full of very good info.
Welcome aboard!