Locash and Licaon_Kter thanks very much for your replies and my apologies for not replying right away. The issue has become moot because I spilled super-hot coffee on my wrist, dropped the phone, and now the touchscreen is totally black; thus it is impossible to use the phone in any way at all. I waited to reply, hoping that the phone would start working again, but it never did.
By some quirk on the umpteenth try, I managed to get F-Droid installed – but I was unable to install any apps from F-Droid.
I did use the file manager app and searched for .Apk. None of those apps I tried to install recently showed up, though one from 6 months ago was there. And to answer the other question, I was currently using Tor browser.
I have become a fan of Android phones now that I’ve discovered F-Droid. So if anyone has a recommendation for a satisfactory inexpensive Android phone, I’d be glad.
Thank you again for your help.