I need your help with a script

Hey! I have a question that I hope you can help me with.

I am looking for a way to do the following:
If input A1 is X, then input in B1 is Y. Plus I want it to happen with every new input that adds to the table (through Zapier).

In my case, I have a column named ID, and another called Description.
Description will be in the format of “This is an event with John” or "This is an event with Sarah… I need a way for the table to automatically change ID associated with “This is an event with John” to “John”, and that of “This is an event with Sarah” to “Sarah”.

That should be done with Script Block, right? And I hit Run everytime I need the system updated? or can I do it through Formula fx?

Appreciating your insights in advance.

Welcome to the community!

If you want a way to strip the words "This is an event with " from the strings you describe, that can be done with a formula field.

REPLACE({Description}, 1, LEN("This is an event with "), "")

However, I suspect that what you want is more complex. Can you give some more detailed examples, perhaps with a screen shot?