“Fake it until you make it” is a terrible saying. It implies that people who “made it” faked it the whole way and it diminishes their accomplishments, sacrifices, and discipline. There is an exception to every rule, but most people who I would call successful worked their tails off.
Instead, a better saying is “fake it until you become it”. When learning a new skill we might feel like an imposter, but if we imitate those who are proficient in the skill, we slowly become what we want to be. What to become a Developer? Great, start faking it and do things developers do. Read tech blogs, write mini programs, create a github, argue about which code editor is better, start running Linux on your personal computer.
Keep faking it until you become a developer.