You can try to fix the following issues on your store and this will improve your store Speed scores, load time, Google page speed scores, Core web vitals. GTmetrix scores.
Fix render blocking resources
Image optimization
JS/CSS files optimization
Lazyload media JS/CSS files
Optimize CSS/JS delivery
Minize HTTP request
Removed unused codes
Fix bad requests ex: 404 links
Optimize Font delivery
Preload files
Optimize APP codes
Here some resources you can follow
https://help.shopify.com/en/manual/online-store/store-speed/improving-speed
https://gofishdigital.com/blog/shopify-speed-optimizations/
https://www.semrush.com/blog/9-tips-for-boosting-the-speed-of-your-shopify-website/
If you need help feel free to contact me Thanks.