option 1 check your theme menu option if provided by the side menu then enable it.
option 2: you have to develop the side menu own..
if you don't know how to code it. then hire an expert or you can dm or email me at firstname.lastname@example.org
Hyde here from Shopify. Great question!
The sidebar menu is a feature of the theme you pick. There are two free Shopify themes that offer a sidebar menu:
And here is a list of the paid themes. Is there a reason why you want a sidebar menu specifically? If you have any other questions, I'm happy to help.
All the best, Hyde.