A young cloth for some reason is the seaweed wakame. If you've never heard of wakame before, go look it up. It's delicious and really good for you. Seaweed is kind of like cloth in the sea, right? Well, this young cloth is nice and soft and thin, like wakame. I imagine young people are soft and thin too, which is why the young cloth gets to be wakame.
若い uses the same reading you learned with the kanji, but the reading for 布 is totally irregular. If you can figure out the meaning, you can use that to remember the reading (since they're the same), but here's a mnemonic to help you just in case:
You're eating wakame and you suddenly spot a 目 (め) looking up at you. You didn't know seaweed had eyes!
In Korea, it's customary to have wakame soup on your birthday.
I'm busy so I simply made dressed wakame and cucumber.
My mom made a miso soup with wakame seaweed and tofu. Do you want some?