Hi, I am setting up a new site in IIS but my CSS,images and JS files are showing as internal server error in the console

It sounds like the Static Content feature was not installed in IIS and/or you are missing the mime types for those files. https://www.syncfusion.com/kb/8633/how-to-enable-the-static-content-for-a-web-page-site-in-iis

i checked and that is already installed