All the troubles come from the hardware.
If your computer supports Qubes at the moment you discover it, your topic doesn’t exist.
But, if not… My advice is don’t waste your time. Prepare yourself to sell your machine on ebay and invest that in a new one. Learn about what Qubes needs to run smoothly, bring 2 USB’s with you (one empty and one with Qubes ISO burnt to it with the third USB Fedora Live’s Mediawriter) and go to the store and test if it will install onto second, empty USB.
Look for the strongest CPU you are able to afford to yourself, and find one with the most USB controllers. Believe it or not, most of new computers will support Qubes out of the box, starting at soonest from Intel gen12 CPUs.
Read recent HCLs here and you’ll see. Don’t make lassie out of grandma.