If you had an opportunity to learn anything in half an hour, what would you want to learn?

Wow, this will be fun! But lets set some limits to your question..

I can learn ANYTHING, granted it is real knowledge, no magic or sci-fi stuff.
You said "an opportunity", meaning its only one shot.
You said "anything", so there is no limits to HOW MANY things i can learn within 30 minutes..

here goes:

How to code in all the most well-used programming codes in existent. Ones that are frequently used. HTML, Phython, C variants, JS variants, Solidity...
All the loopholes on how to move money around. Double Irish and things like that.
How to perfectly read and charm people. NLP and related knowledge.
How to create a brand and all the ways i can monetize it.
How to improve my mental capacity (meditation, present-of-mind .etc)
How to have perfect Situational Awareness in all environment.
SAS survival skills
How to card-count
How to read Law Documents
How to perform real market technical analysis

I think these are enough... with it i can pretty much win in this modern enviroment...