recently I installed alpine linux on my 16gb sd and everything went right (I followed this tutorial https://www.youtube.com/watch?v=RQZRHvmlUU8 ), but I realized that my file system is 200mb/457mb, and I cannot install nothing. On my desktop there is a Volume called mmcblk0p1 which has 15gb left. My question is if I messed up something on the installation and how can I move the filesystem to use the whole sd. Thanks.
Without a description of what YOU did no one can say if you "messed up something".
Raspbian automatically expands the filesystem on first boot, and
raspi-config has an option to expand.
I have never used Alpine, so it is an unknown but this can be done manually on another Linux system.
It can be done on the Pi itself, but requires some expertise and care (depending on the actual partition layout - the very sketchy description implies this may be different to Raspbian). See https://raspberrypi.stackexchange.com/a/78423/8697