I need help to code on GitHub

Since the pandemic started I began to study coding with codecademy. Starting with HTML5, CSS, JavaScript, React and Git. And I’ve been doing great, it really gave me hopes for getting a job that I really need. The thing is that I’m learning React at the moment along with Git. I already have a GitHub account so I can put to practice everything I learned this last year.
But when I clone a repository and open it with VSC, I don’t know what to do! I kinda get frozen when I see all that amazing code, so I start thinking ¿what can I do?
So my question is: ¿How can I be a better programmer? or ¿What advice can you give me to know what to do in those situations?

I appreciatte all your answers.