Brian Coords makes some good points about the difficulty of contributing to WordPress, which is a mark of privilege, as Josepha Haden Chomphosy has noted.
Estela Rueda has some wonderful suggestions for how you can contribute to WordPress core teams with just a few hours a week. Her blog post, Is My Contribution to WordPress too Small? shares “a list of tasks anyone can contribute in less than 3 hours per week to the WordPress Project.”