Shopify Theme Update and Web & Mobile Optimization

1) Shopify Theme Update
Update my fully-customized Shopify theme to the latest version by retaining the existing customization without losing the content and affecting the Shopify store functionality. The workload includes:
- Make a duplicate of the live theme
- Verify any limitations of upgrading from the current version to the latest
- Ensure the update process won’t cause any loss on the basic theme settings, images, custom code, and even app integrations
- Do a customization inventory before performing the updates
- Perform necessary testing before the store go live with the new update

Milestone: Updated theme with all functions works perfectly without losing any content and affecting the functionality.

2) Web and Mobile Optimization
Milestone:
- Improve my web store grade in GTM from F to at least C (Reference: GTM Report: https://gtmetrix.com/reports/mimpikita.com.my/koPuf09J/)
- Improve the mobile score of my web store from 8 to at least within 50 -89 (refer to attached file as a benchmark)