To make the Guides visible only for the new users during their initial visit, you should create a user segment.

Let's say they are coming from the page which has the URL like the following;

So we can create a segment as shown below:

So this guide will only be visible for the users who have visited the page with the "/register" part in it.

You can also send us user attributes if you keep such a log on your own. And then create user segments with these attributes.