[souffle]

yes we use the Charlie chinchilla sand.
It would be better it you had a larger plastic play bin for them if possible then you can also use it for taming.
Get them used to being picked up as this is the best time to do it while they are small. Plenty handling over the box, lift and lay then move on to lift run through hands and lay down then progress to lift and handling.
If they have fluffy bedding you should remove this right away totally as it can cause major problems with bowel blockages or wrapping round tiny toes. Use cheap loo roll ripped up for nesting.
They will be fine so try and not fret. It's always scary doing the first clean. Keep a handful of the old substrate and sprinkle that on top so they keep their scent around.