A store name is a very important factor of an online business as it will help your customer to remember you better and that's what you will be known as online. Here's how to change your Store Name (if you didn't get it right at the first place).
Important note: If you're referring to your store URL (e.x. change testing123.easy.co > testing456.easy.co), it's not suggested as changing to a new name can affect the apps you installed.
1. EasyStore Admin > Settings > General > Store Name
Key in your desired store name at the Store Name field, and once you are done, click on "Save Changes" to apply the new changes.
Attached GIF image as extra reference: