What should my weight goal be? Plus I need advice

Hey there everyone. I've been trying to lose weight by doing cardio and I haven't seen any results. I do a 30 minute workout in the morning and before I go to bed. I eat healthy with a little bit of sugar. I'm currently 70kg and 5'8. What could I do that doesn't take up to much time. Also I'm 13. What should be my weight loss goal be? 😬 I'm trying to lose as much weight as possible before I head off in the high school world.