What can i do to get a full scholarship for rice university in my school and any advice ?

Im a 9th grader or going to be i want to get a scholarship for psychology in rice i have a few other schools in mind but rice is the main goal my brother is in the 10th soon to be 11th grader once school starts and he was chosen to visit rice because he was the best kid in his grade oh yea and his GPA is 5. Something 5.5 i think i feel kinda inferior but i think with hard work i can make it the question is how do i get a scholarship i think every summer ill take some of the classes highschool offers to improve my chances i think that might help im planning to be in debate team, choir, community service program, ROTC, and so much more programs i only have one AP CLASS WHICH IS BIOLIGY. I should be in AP reading and math say MY TEACHERS i dont know. any helpful advice thank you( sorry for the lack of punctuation im in a hurry