What do Beah and his friends take with them when they leave home?

From the text:

On the morning that we left for Mattru Jong, we loaded our backpacks with notebooks of lyrics we were working on and stuffed our pockets with cassettes of rap albums. In those days we wore baggy jeans, and underneath them we had soccer shorts and sweatpants for dancing. Under our long-sleeved shirts we had sleeveless undershirts, T-shirts, and soccer jerseys. We wore three pairs of socks that we pulled down and folded to make our crapes* look puffy.

we loaded our backpacks with notebooks of lyrics we were working on and stuffed our pockets with cassettes of rap albums.