Love your new plants Frenchy!
I will plant them first on the dry side using gritty and coarse mix. Be patient, it takes awhile for them to show signs of new growth. Just keep them warm and dry for now. As Baja said, that Adenium may eventually drop all those leaves, but it will grow new ones and that is your cue it can be watered.
Hopefully by mid Spring you can bring them out gradually to enjoy the outdoors too