Use what you know. Build the backend first. You probably won't know what the frontend requires before this.

Once you know what is actually going to be on your site, you can style the output with CSS and add the necessary interactivity with JS. Browser APIs have mostly standardized as compared to the bad old days. Using them directly instead of libraries or frameworks will keep your site lean and fast.

All of your CSS, HTML and browser API knowledge will continue to serve you for the years to come. In a few years, people will be arguing about a new magic framework.