Can the Apple Care plan I have on the iPad I lost be transferred to the new iPad I purchased?I

Transfer your AppleCare plan - Apple Support

"If you receive a replacement device

If we replace your device instead of repairing it, we’ll automatically transfer your plan to your new device. If transfer of coverage isn’t possible, we’ll offer other options."

If this isn't a replacement device then you can't transfer AppleCare, you need to cancel the old plan (unless you are selling the device in which case it may be a selling incentive) and buy one for the new device.

Contact Apple and see if they can do anything. Refer to this document for ways to contact Apple ➞ Choose your country or region - Official Apple Support

Select your country (also look for "other" regions), then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service by telephone ➞ Contact Apple for support and service - Apple Support