I'd run your website's URL through the Shopify Analyzer. It's a free analysis tool we built for the Shopify community. It'll give you some actionable insights into what could potentially be improved.
We typically recommend implementing the below optimizations to help speed your website up:
**Side note for apps: After uninstalling an app, it's best to go through your main theme files to make sure the code has been removed from your site. It's pretty common for apps to be uninstalled and their code stays in the theme.
Those are some of the most important optimizations you can do to help increase your Shopify website's performance. If you'd like to handle these optimizations yourself, we have a great in-depth guide: How to Optimize a Shopify Site: Complete Guide to Faster Load Speed
If you'd like our team of optimization experts to handle this for you, please feel free to reach out to us at speedboostr.com/contact. Best of luck!