These are historically separate characters, and they're meaningful, but it's relatively unlikely that you can use them as a way of learning Japanese or Chinese characters that you don't already know (as opposed to maybe as a way of helping to remember ones that you do know).

https://en.wikipedia.org/wiki/Radical_(Chinese_characters)

https://en.wikipedia.org/wiki/Chinese_character_classificati...

Also, in the Japanese case, they were borrowed from Chinese centuries ago and commonly given one pronunciation based on what the Chinese word sounded like to Japanese people at that time, and another based on the Japanese translation of the Chinese word.

https://en.wikipedia.org/wiki/Kanji#Readings

So yes, all of this is super-meaningful at an etymological level, but not transparent or reliable, and even trickier with Japanese rather than Chinese, because extra layers like kunyomi were added on top.