As always: It depends.
And of course, there's Parkinson's Law: A task will take as long as it is given time to take.
But, in all seriousness, it is impossible to answer that question without knowing you. You may be ultra-talented, super-smart, have the personality that people want to marry you after one date, so you may be fine with just winging it.
Or you are a nervous wreck with the social skills of Rainman so you may never be ready...
The answer is probably somewhere in the middle. Do a couple of cases, maybe do a practice run here on preplounge and see how it feels. At some point you will start to feel at ease - then you're ready