cuddle fish, how cute. All those arms wrapping around you, little suction cups sticking to you
I assume you mean cuttlefish, like an octopus but with a couple more arms and they cruise around in the water rather than lurking around on the bottom.
Some specialist marine shops will order them in for you, but you will have to pay up front. Then it could be a while before they get one in, depending on their suppliers. If you live near the beach in any country that has average to warm water, you can usually catch your own. However many temperate species grow big and the tropical ones are smaller and do better in tanks.
They are pretty easy to keep, especially if you get a young one. They quickly learn to take different foods but love chasing live shrimp. They will also eat fish.
Keep the water really clean because they are sensitive to chemicals and poor water quality. Keep the ammonia & nitrite at 0 and the nitrate as close to 0ppm as possible, (but less than 20ppm is normally fine). A protein skimmer should be used on their tank along with activated carbon in the filter, (just in case they ink).
As mentioned there are tropical and temperate varieties so you will need to warm or cool the water depending on the species being kept.
If tank size is a concern then you can get dumpling squid (from Australia) and these are tiny (golfball size) and do well in small tanks (100litres or so).