Welcome to the Community, @Taxiarxispurp!
You could use Google Doc’s New Document trigger to trigger the Zap when a new document is created, then use Mailchimp’s Create Campaign action to make the campaign. The Google Docs app also has a Find a Document search action which you could potentially use to find the relevant mailing list document. Gmail isn’t meant for sending out email campaigns, so you’d likely need to handle the send of the email campaign via Mailchimp. But the Mailchimp app doesn’t have a way of adding a new list. And its Add/Update Subscriber action would only be able to add a single new subscriber to a list, not multiple ones.
That said, you could potentially put the Add/Update Subscriber action inside a Looping by Zapier action to run through a list of the subscribers you want to add to a particular list. But you’d need to create the list in Mailchimp first then select that list in the Zap. You can find out more about how to use loops here: Loop your Zap actions
Hope that helps to get you pointed in the right direction. Please do keep us updated on how it goes!