Hi,
As I can see that you purchased for single product – JA Wall only so you will have access to this forum only. You will have access to other templates with JATC (JoomlArt Templates Club) or Developer membership.
Regarding to your question, you can simply duplicate template style in Administrator Panel > Extensions >Templates > JA Wall and assign to your desired menu. This is same behavior with Joomla default.
JA Wall doesn’t use any framework so it works in the same way as default Joomla template. As you can see in our demo site, template provides different styles with different logo for each. After you duplicate template style, you can select a theme and set logo as we did in demo site: http://ja-wall.demo.joomlart.com/index.php/en/themes-and-styles
Let me know if you need further helps.
Regards