It is notoriously difficult to prove that a crack is the result of a manufacturing or material defect. As such, screen damage is often excluded from warranty claims. If purchased directly from Apple, you have up to 14-days to unconditionally return an undamaged item for exchange or refund.
In the first instance, if purchased from a physical store, you should attempt to return the iPad to the same store for exchange; if instead purchased online, check your order information - as this will include contact information for returns.
Otherwise, Apple offer a limited one-year warranty - against which you might attempt to make a claim. If making a warranty claim, again you should attempt to make a claim with your retailer - as it is most often the retailer with whom your purchase contract (and therefore your warranty) principally exists. If unsuccessful, you then have the potential backup of making a claim against the manufacturer’s limited warranty.
If you had the foresight of opting to purchase Apple’s AppleCare+ plan, this being an insurance product, you will have the security of being able to make claim with Apple regardless of fault. In such circumstances, a small excess/deductible charge is made - and you will receive a replacement (usually a reconditioned iPad of the same model and specification) iPad.
An out-of-warranty paid repair will entail screen replacement - which, for practical purposes, Apple may offer an exchange for a renewed/reconditioned iPad of the same model and specification. Given the age of your iPad, the cost of the “repair” when compared with purchase of a newer model iPad may be uneconomic.
You can establish the repair cost in your country/region here:
iPad Repair & Service - Apple Support