I live in Korea, and I'm about to enter college in US. ... I'm afraid of being shot dead like my father's friend. Unlike Korea, US is going through a lot of gun related crimes. If I have to resist against crime, I want to do it as best as I can to save my own life. I hope you understand me.
James, welcome to THR and wish you well on your college studies.
Just a suggestion. If you are planning to spend some time in the US (several years for college?), then why not consider observing/respecting the "ways" of this country?
"When in Rome, do as Romans do"
I grew up in Los Angeles and attended college after my US Army service near the infamous East LA (South Central and Compton was just a few minutes drive by freeway). I slept in my college dorm at night listening to gun shots and police sirens all night, every night. Everyone at the dorm lived in fear of being shot, robbed or attacked (in fact, there were many attacks, robberies and car thefts that took place at the college the years I attended there).
College had security policy for the dorm and everyone attended classes during orientation. We were told by campus security what to do and not do, where to go and what to avoid. Being safe as prey meant staying away from predators. Unfortunately, we were prey among many criminals and gang bangers.
We networked and minimized our exposure to potentially dangerous areas/situations and traveled in groups. Many of us took self-defense classes. Some of us started martial arts training. My TaeKwonDo instructor was an 8th degree black belt and one day in handgun/knife disarming class told us he could not move faster than a bullet. He told us to consider extending our martial arts training to include firearms training to be more proficient in total self-defense.
Although I had firearms training in the Army, it was mostly rifle/military weapons based, not pistol for self-defense. Like many here, I went to a local range and attended firearms training, handled/shot many range guns and did a lot of research on firearms related issues (applicable laws, tactics, legal issues, etc.).
For many in this country, potential to crime is a way of life and reality. But the people have right to freedom and the pursuit of happiness (not sadness from being victims of crimes). There are self-defense laws that protect individuals but only under certain situations and it is your responsibility to learn these laws before using violent force upon another human being (even though they are criminals/gang members - yes, in this country, the lawless have rights).
As stated by many THR members, there are many online resources that you can utilize now to start learning what these applicable self-defense laws you must abide by (law of the land) as a guest to this country. If you have access to a range in Korea, talk to range staff about self-defense classes/training. If you have not, perhaps you might want to start TKD training.
Massad Ayoob is my reference for firearms/legal related issues. You can start with "Answering some well asked questions about personal defense":
http://www.backwoodshome.com/articles2/ayoob97.html
When you arrive in the US, you can continue your "cultural immersion" by following the footsteps of other US citizens in the pursuit of freedom/happiness. Hope you enjoy your stay with us.