Transfer a existing website to wordpress and then use drag and drop page builder

I have a small business website hosting on internet now. I want to transfer the website to WordPress platform and I also want to drag and drop page builder to edit this website.

Are there any easy method to transfer the website to WordPress? And then I can directly edit the website by page builder plugins?

I have transferred the website to WordPress by paste the html code to a blank WordPress theme file. However, I find that it can not utilise the drag and drop page builder tools to edit it.