Here are the main tasks involved in Shopify store theme customization:

1. Header Customization

2. Footer Customization

3. Homepage Design Customization

4. Collection Page Customization

5. Product Page Customization

6. Cart Page Customization

7. Checkout Page Customization

8. Font and Color Customization

9. Navigation Menu Customization

10. Sidebar Customization

11. Banner and Slider Customization

12. Logo Integration

13. Social Media Icons Integration

14. Custom CSS Styling

15. Responsive Design Optimization