I read over some of the other reviews. I'll stay clear of MacKeeper--but I did install it and then uninstall it without buying and now I get an annoying popup reminder.
My question remains, how can I learn to do the clearing of junk that slows the computer? I know how to delete files and photos, but not system stuff.
Unless you're actually experiencing a problem, there's really nothing you need to clear. Deleting caches on a regular basis just slows your computer, actually, since it has to rebuild the caches every time. If you're having a problem with your system not performing well, you'll need to determine the actual cause before you can arrive at a truly effective and time-efficient solution.
First you need to properly uninstall MacKeeper crapware off your machine.
This guy is keeping on top of their B.S. tactics and knows how to REALLY get it off.
My question remains, how can I learn to do the clearing of junk that slows the computer?
First you have to understand how your computer works and what can slow it down, corrupted caches are just one facet of the overall performance issue.
I do have a free OnyX cache cleaning routine here at #6, and if there are corrupted caches then doing the OnyX will rebuild them anew and cure the corruption.
However if you haven't tuned up your Mac before, you might need to do more Steps as needed.
Backup as always
If you want a free evaluation from others online to assist further, then do this and report here the results.