Apparently, ignorance of the law is no defence. This is generally OK if there is some way of finding out. I know that the national speed limit will apply on UK roads unless there are signs to the contrary.
Some rules are less explicit. For example, if you happen to find yourself next to a stranger at a Japanese Baseball match, did you know that you are expected to buy them a gift? And, did you know that it would not be polite to buy them a gift of greater value than they will already have bought you.
The world is quite complicated.
What about when you start a new job at a new company. What are the rules? How do you find out what they are?
Also, are there any customs that extend beyond the rules?
As on the roads, anything that you need to know should be pointed out to you. Simply & clearly.
In the absence of rules you should act responsibly, honestly and ethically as in doing so, you can’t go far wrong…unless you’re working for an irresponsible, dishonest and unethical company. And if you have ‘chosen’ to do this, I think you’ve mistakenly found your way to the wrong blog!