We just have to survive no matter how hard it is and when you're talking about you not ready if you get fired at work, it is normal. If you ask a lot of people, you'd get the same response.
I'm glad that you're not scared of being fired even though you are not prepared. Just make sure that you put in your best and work hard.
I wish you well...
It has been 30+ years of this already - when can I rest? :D