That's good - already you're doing the right things - living life at floor level is quite important until they get to know you. Let them come to you. You can "invite" them of course perhaps by occupying yourself with a toy mouse while you're waiting, or idly flicking a paper ball about - you know, just to distract yourself whilst you're wiating for them to notice you.
Have you got some of the food in that they were eating at the rescue? They'll soon eat when they're hungry, and it's natural you'll worry about that too - all new meowmys do.
Because there are two of them, they have the comfort of sticking up for the other, but they will be very curious, and their curiosity will get the better of them.
Do you know anything of their background or their Mom cat? How old are they right now?
Ice and Cocoa - lovely names. Sounds like when you were cuddling Ice, Cocoa wanted cuddles too.