Working with a client on a second site.

I readily built her first site from scratch in WordPress at [client first site]/wp-admin. Her second site is an existing old site built with Microsoft ASP.NET. Other details: Java / IIS / Windows server.

How can I migrate (or “convert,” not sure of the terminology) the second site described above to a WordPress site? The site in question is www.acaexpert.com. I need to do my design work in WordPress.

Both this site in question and her first are with GoDaddy if that matters (see screenshot).

Thank you, Rik screenshot showing both sites registered with GoDaddy