Very nice. You've done well to get that report posted.
It looks like you have CleanMyMac installed. It's about as close to malware as you can get without actually being that. Use the publishers instructions and remove that from your machine. "Cleaning" apps and "speed up" apps are unnecessary on macOS. And very often they just gum things up, conflict with system software and cause problems. Get rid of ALL the CleanMyMac components.
Your startup drive is an aging 5400rpm mechanical hard disc drive. The read and write performance is in the 50-65 MB/s range. That's terribly slow. You would do yourself a world of good if you could buy an SSD drive in an external case and use that as your startup disk. I would expect a read/write speed of 250 MB/s at least which is much faster than what you have going. The HDD is a severe bottleneck to your Mac's performance.
Otherwise, things look pretty good.
After you've uninstalled al the CleanMyMac junk from the machine, head over to the MalwareBytes website https://www.malwarebytes.com and download a free copy of their utility. Use it to scan your computer for anything that might have been missed by EtreCheck.
I suspect your biggest problems are the two I've mentioned. And if that is the original HDD that the machine came with, I suspect it won't be long before it starts to have other problems. I hope you have all your data backed up. If not, do that today.