Aria here, I’m on the Social Care team at Shopify.
What would you like to change, other than your theme?
You can edit your theme in the background of your store without making changes to the live store. If you go to Online Store > Themes, you will see your published theme at the top but you can also see other themes below:
You can add as many free themes to your store as you like to try them out. If you’ve already purchased a paid theme, you are welcome to download another copy from the theme store without having to pay for it again. You can also duplicate your current theme if you’d just like to make minor changes.
Any changes you make to your menus will appear on every theme so it’s better to just plan those changes then set them up when you are ready. You can set up new products, collections and pages in the background and leave them unpublished while you work on them.
If you really would like to work on a different store that is password-protected, you are welcome to take out a new free trial for that purpose. You can copy themes and products across to that store. Check out our Backups and Duplications guide for instructions.
If you’re looking to make other changes that I haven’t already covered, please let me know. I’m happy to help out.