Can someone guide me on Console & logs, basics?

[dimm]

Hello everyone, right now I need help on Logs and Console information. I just recently uninstalling old uneeded apps. The thing is no one has ever brought about the logs repeated data info. What do I need to know about, delete, look into specific directories? What is okay to delete either within general logs/Console? Any links or youtube advice?
There are 3 imgur photos.

I've haven't done a clean image boot install on this mac, can't even install the latest mac osx.
10.13.6 mac high sierra, 2011 mac
20gb ram

https://imgur.com/a/dxsBEjb

 

[flaubert]

Generally speaking, you shouldn't have to manage the logs manually. The operating system has scripts that run daily / weekly / monthly to rotate and delete log files. However, if you want to be able to manage this yourself there is an excellent freeware utility called OnyX:

Titanium Software | Operating System Utilities for Mac - OnyX

OnyX is a multifunction utility that you can use to verify the startup disk and the structure of its system files, perform cleaning and computer maintenance tasks, configure some hidden parameters of many Apple applications, and more.

titanium-software.fr

Just be sure to note that the downloads are OS-version-specific, so you would need to download the High Sierra version below Catalina and Mojave versions on the page above.