AS you'll no doubt read, you'll probably get a lot of "been there done that" to your post. I have. It's a painful moment when you realize and more accept your device is toast. Water, or liquid in general, is an idevice' worst enemy. Your iPad is gone. I've brought 2 back it seemed from the dead by using all the moisture removal techniques but they were never 100% normal and after all efforts I had to replace. Point of all this is kind of a hand holding or hoping for a gentler realization for you and on to phase 2: acceptance, moving on and getting a new one.
i didn't see its age or if you have AppleCare? If so and it's AppleCare Plus - apple will replace it for I think it's $49ish dollars. If not you'll need to buy a new one or refurbished but if so I'd only get an Apple refurbished one here on this site.
NExt biggie is do you have a recent backup? If so after getting another iPad (or for others reading same for iPhone or iPod) you can Restore your replacement iPad to you backup which depending on its age (backed up yesterday, last week, month, etc.) your Restore will be as good as its age.
so biggest lesson here is Life happens our iDevices are often a big part of our lives and are delicte and can break, die, get lost, stolen, etc. so you must have a backup strategy to protect your data and life.
I Backup using both iCloud and to my computer. iCloud is automatic so hou don't have to remember or think or set alarms etc. and its regularly performed to pretty much remove the human factor and get you having a current backup all the time unless your device isn't on or in a WiFi one regularly
i I also backup manually to my Mac Pro. But don't always remember. you might want to read up on which is more thorough. I feel manuals are. And I'm in the process right now as AppleCare replaced my iPad just yesterday due to a faulty charging system. Luckily I have both my trusty iCloud ha hip from 835am yesterday and a manual from the night before.
after a restore you'll usually need to look to fI'll in the gap between your backup and when your device died or was lost, broke, etc.
SUMMARY:
try to always get AppleCare it's worth every penny For 2 years including unlimited phone support.
Have a backup strategy AND DO IT!
sorry about your loss. If you don't have AppleCare or a backup we'll hold your hand as best as possible but be prepared to get a new iPad the Air2 is awesome. Good luck.
