Welcome to the forum and so sorry for your ordeal. Pleased to hear that you are uplifted and trying to adjust to this. Alot for someone your age.
Ask for all kinds of samples. It's all trial and error in the beginning.
For myself, I use Convetec Moldable Convex wafers. My stoma was inverted, so I needed convexity. Moldable took the quesswork out if it. The stoma paste didn't work for me, using a ring did...Eakin Seal. You've ordered the Coloplasts ring, hope that will work. When my skin was raw post-op, I alternated between powder and wipe, several times. The powder really hinders the weartime, so getting a good seal and letting your skin heal without it, is what is best in the end. Do you really need to apply the powder? What has the WOCN said? Others will chime in. You can also go through past threads and see what tips will assist you. My biggest tip is using a hairdryer. Maybe not for now if your skin in a compromised state.