Hello Thuy. If you really want to, you can learn all on your own. But it is true, having someone teach you will speed up the process. Have you tried looking for videos on Youtube about “learning hangul” ? That would be a good way to start. Also, I made a video course for beginners that you can check out — it’s all in English and I speak quite fast in the videos. So if that is okay with you, you can check out that course.
You can also check out “Korean pod 101” on Youtube, they have a lot of helpful videos as well. Even if you can’t find a teacher, Youtube has many teachers who already made videos that can help you.
I think you can do it! Just do something everyday and keep going. Eventually, you will learn. Good luck!