It’s impossible to provide a definitive answer that applies to you, but it is not uncommon for a retailer to re-shrink-wrap products.
If prompted for a Passcode, you may have another problem coming...
Without the existing passcode, the device will need to be “restored” - which may result in an Activation Lock. If this occurs, you’ll need the AppleID and associated password of the previous owner that set-up the iPad.
Anyhow, without the passcode, your options are limited to trying to recover the iPad. If an Activation Lock is encountered, then it’s game over.
If you iPad is disabled, or the passcode is unknown, you’ll need to follow this process:
https://support.apple.com/en-gb/HT211078
You’ll need access to either a PC (with iTunes installed) or a Mac (with iTunes or Finder - as appropriate for the installed version of MacOS).
Here are the Apple support pages that outline the Activation Lock - and the only mechanisms by which it can be turned off:
https://support.apple.com/en-us/HT201365
https://support.apple.com/en-gb/HT201441
As you will discover, unless you are the owner of the AppleID that was last used to activate the device, or unless you can secure the cooperation of the previous owner, you’ll not be able to defeat or bypass the Activation Lock. Without documentary evidence that you are the original owner (such as sales receipt showing the serial number), Apple won’t assist - and nobody here will be able to help you.