It looks like you have sufficient Disk space and RAM.
If your battery is EOL (died) or not holding charge...
Mac will cut the CPU clock speed to 1/2 of maximum that will impact all and any operations.
Install Intel Power gadget to verify your CPU, this is an example of normal speed CPU.
Use the Activity Monitor to see who is responsible. Here are my examples.
Notice the Disk activity as Data/Sec
Finally about the battery (check this on your computer)