Let's try solutions for speed up your store below :
- Setup store to production model
php bin/magento deploy:mode:set production
- Enable JS & CSS optimization
Go to Stores -> “Configuration” in “Settings” Section -> “Developer” in “Advanced” Tab -> Section “JavaScript Settings” (Fields “Enable Javascript Bundling“, “Merge JavaScript Files“, “Minify JavaScript Files” change to “Yes”)
Go to Stores -> “Configuration” in “Settings” Section -> “Developer” in “Advanced” Tab -> Section “CSS Settings” (Fields “Merge CSS Files“, “Minify CSS Files” change to “Yes“)
- Content Delivery Network
STORES -> Configuration -> GENERAL -> Web -> Base URLs (Secure)
then insert your HTTPS URLs in here and bring your customers fast loading speed.
- Have caching enabled
Go to Stores -> “Configuration” in “Settings” Section -> “System” in “Advanced” Tab -> Section “Full Page Cache” -> Field “Caching Application” change to “Varnish Caching“, than configure it.
- Images Optimization
A. You image must be compressed.
B. Product Image should use JPEG format
C. Logo and layout should use PNG or SVG format
- Enable Flat Categories and Products
Go to Stores -> “Configuration” in “Settings” Section -> “Catalog” in “General” Tab -> Section “Storefront” -> Fields “Use Flat Catalog Category” and “Use Flat Catalog Product” change to “Yes”