Skinnies eat more. Not pellets, not much more in the way of fresh food (you don't need to double their portions or anything), but definitely prepare to gk through more hay. Their faster metabolism, which gets spent on keeping them warm without fur, means they need to eat more to keep a stable weight. They also need their surroundings to be warm enough to maintain their weight.
They're also vocal. Very, very vocal. And they don't like cold things and that includes your hands. I have Raynauds, which didn't make handling fun, but if you need to then wrap them in a small blanket or similar.
And be prepared for the poop. All that extra food has to come out the other end.
No clothes, same as any other guinea pig. And they don't automatically need their skin moisturised either. If they do have a skin issue get it checked, don't immediately think it's "just" dry skin. Coconut oil can do more harm than good.
They're small. It's a side effect of being a skinny. Bann was on the larger side for a skinny and even he was only 1.02kg at his top weight. To compare, Mourne got weighed at 1.2kg by the vet the other week and he's not overweight.
They're prone to fat lumps. Keep an eye out for that.