Redesigning an HTML Website to WordPress

Hello everyone,

My client has a website dating back to 2011, and it’s certainly not built on WordPress. The client wants me to redesign the site, and I’m facing the following challenges:

1. Since the website wasn’t originally created in WordPress, is it possible to redesign it, or does it entail building a new site from scratch? I would greatly appreciate it if someone could explain the process involved.
2. What can I do to ensure that the website doesn’t lose its Google search rankings? Are there specific steps like using htaccess redirects?
3. The website currently uses HTTP instead of HTTPS. If I transfer the domain to a hosting provider that provides an SSL certificate, will the domain automatically switch to HTTPS?

I’ve never encountered these issues before, so I appreciate your understanding. I hope someone can guide me through this process because, I won’t deny, I feel a bit lost on this matter.

I hope someone can assist me. Best regards ??

The page I need help with: [log in to see the link]