When I started as a self-taught mechanic/repairman/technologist a long, long time ago, I used WD-40. Then I quickly found out that it gummed up sleeve bearings, didn't really provide semi-permanent lubrication, and didn't free up frozen and rusted bolts.
You have to use the correct lubricant for the job. And for just about every job, WD-40 is not the answer. Just stay away from it. Stop buying it.