Try scanning your site with this scanner that is tailored to Shopify https://analyze.speedboostr.com/
It will give you a breakdown of some key factors you can improve on.
If any optimization opportunities are present, it'll give you some great feedback on what can be done to improve your site's performance. We have an in-depth guide you can reference as well: How to Optimize a Shopify Site: Complete Guide to Faster Load Speed.
The main things you'll want to consider are:
Those are some big ones, but you can check out the free guide I linked above for all of our optimization recommendations. If you need any help, please feel free to reach out to our optimization team at speedboostr.com/contact. Best of luck!