2019 iMac is extremely slow

I did search in Apple support for this and there are hundreds of people in the same place as I am. My imac running Big Sur is beyond slow. it's a 21.5" 2019, 3ghz 6 core intel core i5, only 8 gb of memory, with a 1T Fusion drive.

I'm not very computer literate so that is going to be a huge problem. I turned it on this morning and everything loaded after 22 minutes. And I click on the Chrome icon and it opened to a white screen and it took 16 minutes to get the the Google search box. I tried to open Safari and it wouldn't even open. Mail 2 times out of 3 stops responding. If it loads it takes up to 10 minutes.

I have Apple Care support and they have NOT been helpful. I have a 2007 iMac that still works and it's faster than this one. Apple support just told me, "oh don't use Chrome its slow use safari. Well it won't load half the time and I have 1 Password and it won't work with Safari.

This thing is just a complete f**king mess. I work online and I need a computer that works well and fast. It got way way slower after the upgrade to Big Sur (Apple Support told me to download it and said it would fix my problem, it's way worse now).

I have a friend that said I should get an external 1 TB SSD and use that but I don't know how to make it work. I watched a few youtube videos which said I have to load a new OSX to the drive and migrate all my files to it. Huh? I have no idea how to do that. This computer isn't yet a year old, I can't believe how slow it is, how often stuff just won't load and how often when I go to force quit the program (it can be Chrome, safari, mail, messages, anything) is "not responding." Never had I had such a crappy computer.

Is there anything that a novice can do to make this faster?

Thank you,

Susan