https://duckduckgo.com/?q=kalanchoe+propagation&t=ffcm&iax=videos&ia=videos

a pic of the other plant.. will probably get you an ID.. so you can do as per above ...

ken

Put the leaves in bright location. You will see the roots and tiny leaves start to sprout out of the end where the leaf was attached to the plant, for the type of leaf in your pic. There is no reason to add any moisture until and unless some roots form. The leaf in your pic looks like it came away from the stem intact. That is important. Most leaves that tear instead of remaining intact will more likely rot than root.

There's no reason to move the leaf already on the soil surface, but know it's not necessary for future propagations. It's fun to watch them on a windowsill, and months can pass before moisture becomes critical. All of the moisture in the mama leaf will be absorbed before that stage, and with a mass of roots already at the stage below, most people would have moved them to soil long before the mama leaf is gone.

thank you for the detailed response (:

My pleasure! Realize I forgot to say, try to put leaves right side up. Your pictured leaf looks like it is facing the right way. Upside-down leaves often sunburn even if placed right next to where the plant is, where it is used to being.

I hope your worst problem ends up being trying to figure out what to do with all of them.

As Tiffany said, there is no need for extra moisture - some ppl spray the leaves, but they could rot fast if too wet. Kalanchoe may or may not grow new roots. The leaf you had to cut will most likely not grow. Few plants will grow even from torn pieces, but not many. You didn't say what plant was the leaf from...if same/similar to the pic you posted, it will not grow. Kalanche tomentosa grows easy from the leaves...