Be ambitious enough to apply and humble enough to learn the job once you get it.

Two different muscles are needed here, and most people are strong in only one. Applying takes a bit of nerve: you have to believe you could do something you have not done. Then the job starts and the nerve has to step aside so you can be taught. People who keep performing confidence past that point never learn the work.

Think about which half comes harder for you. If it is applying, send one application this week for something you are not sure you are ready for. If it is learning, pick one thing on shift and ask someone to show you properly.