Have you lost it in your house? Has it been lost somewhere in public and been stolen? If you have lost it either way, you can try to look up where it is at using "Find my iPhone" on another device or on the iCloud https://www.icloud.com/ website by logging in with your Apple ID and it should show you where it is at or where it was last seen. If the iPad doesn't have Cellular and isn't connected to wifi currently it will tell you where it was last located. If it's connected to wifi or cellular then it will tell you where it is currently. It will also give you the option to erase the iPad or put it in Lost/Stolen mode in which it will display a message for someone to get a hold of you if they found it. If it has been stolen and wiped, then the person that has it won't be able to do anything with it, but unfortunately you won't be able to do anything with it either. If it's lost in your house and you are just trying to locate it, you can have it play a sound (even if it's on silent) to get it to play a tone so you can locate it.
If you have another device, use the Find My iPhone app. It will locate your iPad, and even make it play a sound
, wether or not it is muted.
Can’t find my iPad