@marlenedencker27 What you can do is to use segment. If your subscribers are added to a form, tag, the sequence you can create a segment like this.
In this segment, you have the option to add if your subscribers are added via form, sequence, and tag.
Then once you create this segment you can go ahead and create a new tag and use bulk action 30
You can add them to the new tag. But make sure that a new tag is added in your visual automation as empty before you add them to that new tag from segment via bulk action.