Don't be afraid to have your own personality and self confidence.   Girls like guys who are comfortable with themselves and have a lot of self confidence. If you are creative, get involved with a music group, art group, or theater. You will meet, and hopefully attract, girls who have similar interests and talents. Stay involved in your sports, arts, or school activities even when you are interested in chasing a girl.  Don't spend 100% of your time thinking about the girl you like or trying to impress her. You will need balance in your life. Keep yourself occupied with your own hobbies in the meantime. Hopefully, your crush will have some of the same interests. Developing these can help you spend more time with her. A guy who has a good group of close friends will be attractive to girls.  This can be a good way to meet girls through your own social group. Invite the girl you are interested in to participate in activities with you and your friends. Friendships are important. Make sure that once you start dating a girl, you don't neglect your friends. You don't want your grades to slide because you are distracted by trying to make a girl like you.  A guy with good grades will be more attractive to girls than a guy who is failing all of his classes. Participate in your classes. Girls will notice this if you are confident in class. If you aren't doing well in a class, you could ask a girl for help if it's a subject she is good at.

TL;DR in Vietnamese:
Hãy là chính bạn. Trau dồi sở thích của bản thân. Duy trì tình bạn. Tập trung vào việc học ở trường.