To change the logo and favicon of your store follow the steps mentioned below :
1. Open your OpenCart admin panel and go to the System ➜ Settings section then click on the Edit button as shown below :
2. After going to the edit page, go to the Image tab to change the logo and favicon.
Hope this tutorial will be helpful to you!
Related Tutorials For OpenCart :
How To Manage Product Banners | Opencart 3.0