Hello MrsBeavers,
Thanks for reaching out to the Apple Support Communities. We understand you are experiencing some issues opening downloaded files on your Mac. We are happy to help provide some guidance.
Are you able to download files successfully on the Mac, will it not initiate downloads, or will it download the files just fine but just not open the files?
If you can’t download an item from the web using Safari on Mac
What happens when you try opening a downloaded file? Do you get any sort of error message when you try opening them? The more information you can provide, the better the Apple Support Communities can provide assistance.
Keep us updated, we are here for you.
Best Regards.