Dear 한태호,
you may find that this page offers a simpler and quicker way of getting
GQRX installed on a Raspberry Pi 3:
http://gqrx.dk/download/gqrx-sdr-for-the-raspberry-pi
The advice to use a clean OS install on the microSD card is very sound.
It's probably best to use several microSD cards so that one can
experiment freely, with little pain when things go wrong and one has to
start from scratch (the beginning) again.
HTH, Good Luck,
Robin, G8DQX