I suck at singing, how can i get better?

I want to sing good, but i dont want to spend my parents money on singing lessons. Im a boy, and i know theres great singers who never spent money on lessons, and somehow got good. I know i have to sing, to get better. I do sing, but i want to hit every note right. I have the whole summer to get better, thanks! please answers from people who answered this question a long time ago, before consulting me, thank you!!!!!!