What Lời khuyên would bạn give to someone who wants to be a writer?

Write what bạn want to write. Don't stick to some specific genre because bạn feel like bạn have to. Write whatever story bạn want to, however bạn want to. bạn wanna write a horror story one ngày then create a comedy the next, go right ahead. What bạn write is all up to you. Don't your creativity.
Also, don't be upset if your first stories get shot down. It happens to everyone and it's good to get the practice in. bạn may look back on those stories in the future and say, "Wow, that was shit", but it's always good to get in the practice and you'll be glad that bạn were able to improve with time and practice