You’re never going to be completely ready.
You just have to take what you’ve got and go for it. Even when you think you’re ready for some things, there will always be others you’re not quite ready for.
You have to be honest with yourself. This is where you are right now. This is what you have to offer. This is what you’re capable of.
Now get out there and perform.
All you can do is learn from your performance, apply that knowledge and get back to practising.
Then be willing to give it another go.