I need advice

Hi. Im currently employed. Great salary, but i feel i could do more. I was thinking of getting into medical coding so I can have a higher salary. But I lack the courage, also it would take me a while. I really dont want to be stuck in my situation right now because i somehow feel I can do more and be in a better position. I am just scared of what lies ahead. Hope you guys can give me advice. Im in my mid 20s. No kids. Just a partner i live with.