The 1st gen iPad Mini is a nearly 11-year old device.
This came out in 2012.
It is simply too old and almost all third party app developers have abandoned support for these old devices and old iOS versions by 2018.
This is not the fault of Apple, at all.
Sorry.
You need to consider that it is 2023, now.
iPadOS 16.5 is here.
These nearly 10 to 12-year old iPad models are obsolete.
These iPad models will be 6-7 OS iterations behind, now. Soon to be 7-8 iterations behind.
Lots have happened with iPad and iOS ( now iPadOS ) in 11 years!
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 afford 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 16.
2015-2017, 12.9 inch screen iPad Pro models ( 1st gen Pencil support )
2016 9.7 inch screen iPad Pro models ( 1st gen Pencil support )
2017, 10.5 inch screen iPad Pro models ( 1st gen Pencil support )
2018 11 inch or 12.9 inch screen iPad Pro models ( 2nd gen Pencil support )
2020 11 inch or 12.9 inch screen iPad Pro models ( 2nd 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 )
2020, 10.2 inch screen iPad 8th gen models ( 1st gen Pencil support )
2021, 10.2 inch screen iPad 9th 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 )
2021 10.9 inch screen iPad Air 4th gen models ( 2nd gen Pencil support )
2019, 7.9 inch screen iPad Mini 5th gen models ( 1st gen Pencil support )
2021 8.3 inch screen iPad Mini 6th gen models ( 2nd 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 old iOS devices.
Sorry & Best of Luck to You! ece