You can adjust the sample template to your needs or completely change its structure by creating a new custom email template right on the Campaign creation page.
To do so, either load the existing template and modify it or create one from scratch if that is more convenient.
This template will be available only for the particular campaign it was created within. Therefore, if you'd like to use the adjusted template for several campaigns, navigate to Marketing > Email Templates > Add New Template and load the "Abandoned Cart Email" template. When the template is loaded, you may freely change it according to your requirements.
When a new template has been created, please go to Marketing > Abandoned Cart Emails > Campaigns, open the required campaign, and in the Schedule tab, choose your newly created template and save the campaign: