How much memory should be used.

Virtual Memory Information:

Physical RAM: 96 GB

Free RAM: 67.80 GB

Used RAM: 15.29 GB

Cached files: 12.90 GB

Available RAM: 80.71 GB

Swap Used: 0 B

You have plenty of RAM. This says:

• Applications are using 15.29 GB of RAM.
• You have 80.71 GB of available RAM. 67.80 GB is completely idle, and the other 12.90 GB holds cached data that macOS could dump if applications suddenly needed the RAM. (Breakdown off by 0.01 GB due to rounding error.)
• The system isn't doing any swapping to SSD to simulate more RAM, because there's no need to do so.

By far the easiest way to cause poor performance, instability, overheating and crashing is to install ANY third-party speeder-uppers, Cleaners, Optimizers, or Virus scanners. or a VPN that you installed yourself. The main reason is that they are relentless in scanning your files, non-stop, looking for things virus-like patterns in Everything. When completed, they do it all again.

The idea that a third party, with no special knowledge of the inner workings of MacOS, can somehow find a simple way to protect your computer — that is not already being done by MacOS itself — suggests that the MacOS developers are somehow "holding out on you". That is absurd.

You should remove any and all (other than Apple built-in) virus scanners, speeder uppers, optimizers, cleaners, App deleters or VPN packages you installed yourself, or anything of that ilk.

Third-party file Sync-ers such as DropBox, BackBlaze, OneDrive, or GoogleDrive can ruin performance, but are not inherently dangerous.

Effective defenses against malware and ot… - Apple Community

Consider downloading and running this little "discovery" utility, Etrecheck. it changes NOTHING.

it contains little tests for speeds of devices, CPU utilization, memory usage, energy usage and a digest of recent problems, in one easy to use package. it does not even need to be Installed.

if you follow the directions faithfully, its report (pre-laundered of all personally-identifiable information) can be "Shared" to the system ClipBoard, then Pasted into an Additional text window in a reply on the forums.

How to use Etrecheck Pro for free

Major Issues:

    Anything that appears on this list needs immediate attention. 

    Security updates disabled - Security updates are disabled. This computer is at risk of malware infection.

    Apple security disabled - Apple security software is disabled. This computer is at risk of malware infection.

 Low disk space - This computer is running low on free hard drive space.

Your disk is essentially FULL. For context, your Mac consumes over 9 GB or space just going from a cold start to up and running. The amount you have free leaves you on the brink of a 'disk full' disaster.