Dear new developer,
This post is worth reading in full, but is advice that holds for all developers, not just folks starting out.
I especially liked
Fight for what you believe, but gracefully accept defeat. Understand that sometimes your ideas will be overruled. Even if you do turn out to be right, don’t take revenge or say, “I told you so” more than a few times at most, and don’t make your dearly departed idea a martyr or rallying cry.
You are not your code. Remember that the entire point of a review is to find problems, and problems will be found. Don’t take it personally when one is uncovered.
But all of them are good. Go on, go read it.
Note that these principles (though not the post) are from a book published in 1971. Technology changes yet people remain the same.