My iphone 6s got wet and has died. Is there some way I can retrieve my contacts? Are they on a 'cloud?

You really need to talk to whoever set up your phone. If it was an Apple store then it is very likely that your contacts were linked to your icloud email account.

You will need a new iphone from the Apple Store and if it is set up exactly the same way using the same Apple ID and email accounts then the contacts will be out there in the ether.

Now can you remember your apple ID and password? 🤞

(don't post them here!!)

That depends. Did you set up your phone to automatically back up contacts on ICloud? Did you ever back up your phone on your computer?