Here are some steps you can take to migrate an online store to a new platform: 
- Prepare: Create a new account on the new platform, learn the interface, and configure your store settings. 
- Migrate data: Identify the data to be migrated, clean it up, export it from the old platform, and map the data fields. 
- Install: Install a theme and extensions on the new website. 
You can also use a third-party platform migration app to automate the process. For example, LitExtension offers apps to migrate between platforms like Shopify, BigCommerce, WooCommerce, and Squarespace