I wouldn’t recommend the iPad mini because it is too small. Check out the normal size iPads up to the large 12.9 iPad Pro. You can get a cover for the iPad that allows you to hold the back of the iPad with the palm of your hand and it swivels, less strain because your not using your fingers to hold it.
The iPad also allows you to read in normal light mode and in dark mode depending on what’s easier for you to read in.
I have over 45 years running Apple products and 44 years in IT, if you have any questions about the iPad, how to set it up, back it up, update it, send me a private email, I don’t charge for this advice

And I wouldn't recommend the iPad because it is too large and too expensive.

Look at the options and the features and find what works for you. The e-ink of the Kindle Paperwhite is excellent for reading outdoors and the device is inexpensive and easy to hold. The heavy-duty processor, large screen, and large processor of the iPad are great if you are doing much more than reading but they come with a heavy weight and a heavy price tag.

when you pay your 40 fee you also have access to the Marion county library

Don’t know how those “reciprocal agreements” work but I sure would like to know the answer to this question.

I respectfully disagree that the mini is too small. It’s actually just right for most people. You can make the text larger on a mini but you can’t make the physical size of a large iPad smaller! To each their own though.

Kindle Paperwhite
 

Kindle paper white can be read indoors and outdoors. Books, magazines can be borrowed and downloaded from local libraries. You can also purchase books from Amazon.

I suggest to search for free kindle books on Amazon. The available books change frequently.