It’s a ~fifteen year old Core 2 USB 2.0 HDD Mac. It’s inherently slow. And it is also very much overloaded.
That HDD isn’t helping things:
Why is my hard disk drive iMac so slow? - Apple Community
Use an external SSD as your startup disk … - Apple Community
Unfortunately for any external SSD upgrades, that iMac has only USB 2.0, which is going to make an SSD not that much faster than an HDD.
Some Apple authorized service provider might be willing to upgrade the internal storage, if you pay for that and for an SSD from them. Thar’ll be faster than USB 2.0.
It’s running a torrent app, which is unwise for performance reasons, and can be unwise for other reasons. Torrents combined with a modified hosts file too often means trouble, too.
Remove MalwareBytes, Norton, CCleaner, PeerGuardian, Google, GarageBand, Chrome, the memory cleaner, the SanDisk add-ons. If the printer supports AirPrint, remove the HP add-ons. I’d likely remove that NETGEAR stuff is, too. Basically, unload everything you don’t absolutely need.
But looking st that configuration, and given everything that’s already happened to this Mac, I’d get two good backups, build a bootable installer, then wipe it and reinstall macOS with just the apps you need and those apps loaded only from known-good sources.