How to find out what model my iPad?

Not sure which iPad you have?  Use Apple's own definitive identification guide:

Identify your iPad model.

..LoveofOwls..

Some sites that buy sell or trade apple devices &/or apple gear

use all identifier details; online in database, most're free to use.

'everymac.com' has much online including iOS devices & macs.

'sell-your-mac' also shows more details than you've shared here.

This SYM is by OWC, similar to other OWC sites, with useful free

info and not parallel to their main online macsales.

If your example has both cellular and wi-fi, that'd have a SIM card.

https://www.sellyourmac.com/mac-product-guides/ipad/me993ll-a-ipad-air-wifi-cellular-16gb.html

As satisfactory results from any search; through Duck-duck-go, google

or any other; the more you know can affect accurate detail output too.

A Google search shows it was manufactured in 2013… 11 years ago.