There is also time dilation from motion through space (motion through space + motion through time is equal to the speed of light, so as you speed up, your motion through time slows down) as well as time dilation due to gravity (like when near a black hole I think).
I'm also not a physicist, but read some popsci books in my youth like "A brief history of time" from Stephen Hawking (it's written for normal people). That's probably the best book you'd want. He later wrote a more modernized version called "a briefer history of time" as well. They both cover time dilation from a high level iirc. Of course, to truly understand you'd need to learn the math. I'm looking forward to doing that during retirement in a few decades.
Not trying to be a dick, just not qualified to explain this myself