Hello @RebeccaA773. It's great that you would like to start using a mobile template for your emails! Just like you said, the number of people reading their emails on mobile devices has been increasing and having your template be mobile friendly ensures that it will display correctly for your contacts on a mobile device. It is possible that the template that you are using at the moment isn't considered to be mobile responsive. We do offer a charged service where our Custom Services team can create a mobile responsive template for you using your logo and colors. But I can certainly show you how to find a mobile responsive template within your account (no extra charge for these!)
In your account, click on the "Create" button
Then click on "Send an Email"
In the search box, type in "mobile responsive". This will bring up all of our mobile responsive templates.
You can tell that a template is mobile responsive by finding the mobile icon to the right of the name of a template.