Back to the OP’s question

I serve as an EMHC, and we are scheduled for all four weeks of a given month, and then have a couple months off. We have very little trouble, if any, with no-shows. Those who take our Lord to the sick are either part of the particular ministry group that regularly does that, or sometimes we just know someone.
When an elderly daily communicant landed in the hospital for a couple weeks, I took her Communion many times. I don’t know if there are rules about frequency, but I knew that as a (nearly) daily communicant myself, I would really appreciate someone coming frequently, so that’s what I did, with the blessing of the priest and deacon.
The experience? I almost fainted the first time I served, and it is still quite overwhelming. I only minister the Precious Blood during Mass, and I hope I am never asked to minister the Body of Christ, because I don’t know how I would manage to handle the Sacrament itself (Himself?) so many times. It can be nerve-wracking to serve a school Mass, because the kids are not always careful handing back the chalice, and I have to pay special attention to keep from spilling. When I took our Lord to the hospital for my friend, I rode across town on my bike, and had ten minutes every day to think about how amazing it was that Jesus would permit His Presence to be carried out of the church, let alone on a bicycle!
Our training was very minimal, more along the lines of choregraphy, but the priest and deacon have always been open to my questions. We have no nominating or commissioning.