Do not give up just yet.
You need, at least, a 10 ot 12W Apple power/charging adaptef block to charge ANY iPad.
The 5W iPhone power/charger block is simoly NOT enough power to charge up an iPad battery.
Especially an iPad that has not been charged up in 5-years!
If you have or purchase an Apple 12W power/charging adapter, try leaving this iPad on charge for 24-36 hours to see if the battery will charge from a deep uncharged state.
Tap the link below.
https://www.apple.com/shop/product/MGN03AM/A/apple-12w-usb-power-adapter
If NO success, then this iPad is dead and done.
LobsterGhost is correct about the age and usefulnees of this iPad, now, in mid 2022.
Apple has stopped fully supporting this iPad and third party app support is, now, quickly dwundling in 2022.
Sorry.
You really need to seriously consider a purchase of a new iPad model OR a much, MUCH “newer” and less expensive, refurbished or used iPad models, from better known, trusted sources, like other Apple product/device retailers/resellers, some locally or from online, on the Web/Internet, capable of running the latest iPadOS versions.
There are PLENTY of newer, older iPad models that can run the latest, current versions of iPadOS.
If you need OR ONLY able to purchase older, less expensive iPad models, look at older IPads from 2015 and later.
All of these older model iPads below CAN, currently, run the latest releases of iPadOS 15 and the up and coming iPadOS 16, releasing sometime in the Fall of 2022.
2015-2017, 12.9 inch screen iPad Pro models. ( 1st gen Pencil support )
2017, 10.5 inch screen iPad Pro models ( 1st gen Pencil support )
2017, 9.7 inch screen iPad 5th gen models ( NO Pencil support )
2018, 9.7 inch screen iPad 6th gen models ( 1st gen Pencil support )
2019, 10.2 inch screen iPad 7th gen models ( 1st gen Pencil support )
2020, 10.2 inch screen iPad 8th gen models. ( 1st gen Pencil support )
2018, 11 inch or 12.9 inch screen iPad Pro models ( 2nd gen Pencil support )
2019, 10.5 inch screen iPad Air 3rd gen models ( 1st gen Pencil support )
2019, 7.9 inch screen iPad Mini 5th gen models ( 1st gen Pencil support )
Get the largest internal data storage model you can afford as NO Apple iOS device has ANY expandable storage.
I am sorry that you had to learn all of this, but this does not change any of the facts regarding these older iOS devices.
Sorry & Best of Luck to You!