I downloaded Big Sur OP Sys and ever since I have been having trouble receiving email. When I receive it the pictures don't show. Also, with the Safari Browser it sometimes doesn't load web sites even though they will load on Google Chrome.

Profile showing Big Sur 11.2 which is out dated. As of this writing - there is a Big Sur 11.4 which fixes bugs and security issue from previous versions of Big Sur. This may or may not help fix your issues

If you can’t send or receive email on your Mac

Any Third Party Applications that will interfere with the normal operation of the OS, alter, modify, remove or delete or attempt to do so is an invitation for disaster and may require a Reinstallation of the OS.

There are no known Viruses in the wild that self replicate and affect macOS. There are Malware and Adware that does affect macOS and are often times downloaded as part of an Application from Third Party UnTrusted Site and get installed along with the Application.

Suggest downloading from a Trusted Developer and Respected ASC Contributor the application Malwarebytes for Mac. It is free or paid for added features. Run the Application and it should remove the malware / adware. Once done, restart computer and test.