I need help for the automation in ML when people join a group via a zap.

When people join my spreadsheet, they get copied to my Mailerlite group via zap. Unfortunatelythat way the subscriber doesn't get the double opt-in mail. (or how do I do that?) Therefore I set up an automation with an email telling them to click a button in order to get the mail with the download button (freebie). That works so far. But then I had to put a delay of some days before a condition (if he/she had clicked specific link (opt in)), the subscriber gets the next email with the pdf-link). But that means the email with the freebie-link will first get to the subscriber after those several days later, isn't it? Where is my mistake in thinking? What do I need to do in order to make that work?