From my limited experience, here are some answers. My kefir grains came from the Kefir Lady in a small ziploc bag. I put these in a quart jar and added 2 cups milk. Each morning I pull out the grains with clean hands and put these in a new clean jar then add 2 cups fresh milk. This gets left out on the counter with a cloth cover. The “old” kefir milk can then be consumed, or put in the fridge to keep a while, or left out on the counter to get “stronger” for another day. The smell and taste is a bit tangy and sour. It gets more tangy and sour the older it is.
Try a search for the Kefir Lady’s website and Dom’s Kefir website (he’s Australian) for more information.
I like growing it so far; it’s like keeping a pet you can eat!