I hope this is the right spot to post this. Believe me. I have tried to find this simplified version everywhere. However, I had a head injury that makes it harder to piece some of the finer details together to achieve my goal currently. Firstly I bought/donated to Humble Bundle and one of my codes runs out 12/31/25. I want to make sure I have these downloaded. I also want to read them on my fire 10 tablet. I managed to get 2 books on there with no cover art. Those were downloaded in PDF format and open in Microsoft 365 and my Kindle app. However, I downloaded most of these other files onto my Fire tablet but cannot figure out how to use them or convert them into Microsoft 365 and get them in my Kindle app.

-What is actually the best format to download? (PDF,ePub,CBZ/CBR) -Can I download each different file version on my computer and convert them and send them to my Fire 10 tablet? -since I can see the files on my Fire Tablet how do I actually access those PDF files and use them? -can I just take out the SD card in my Fire Tablet and load the comics in any format I want on there? Then plug the SD card back in my tablet? -is it best to try and store these on my PC for access later, downloading all the formats (epub, CBZ/CBR) available? I don’t want to lose these down the road hopefully.

Any help and guidance is appreciated. Thanks. 🙏