Having the self-belief that you will be able to figure things out as you go along is critical to success at anything hard.
Get started and trust yourself. No one has all the answers at the beginning.
The home run theory of careers:
What matters is eventually hitting a home run, and the way to do that is training hard and a lot of at-bats. You only have to be right once, and it's ok to be wrong a lot of times.
Be bold. Move fast. Work hard. Ignore haters. Keep swinging.