What is the initial price of BTC and other coins/tokens?

Hello, I would like to ask about the initial price of BTC or ETH or any token.

how they calculate it? is there a rule that we can depend on? or there is websites provide how to add initial prices?

if I have an admin panel, and the panel asks for the initial price how can I fill it?

Regards

Sorry, I am not sure, and what is this chart? Where did you find it?

no issue, I will ask in other place.
regards