becoming a clinical psychologist in the us

hi everyone! i'm a sophmore in hs right now, and i think i want to become a clinical psychologist. i've been researching, but i want to hear actual people's opinions:

what should i do in high school and college to set myself up to get accepted into a clinical psychology phd program?

what do i need to get into a psychology program?

what is the one piece of advice you would give me?

thank you so much! :)