Switch properly from HTML website to WordPress without hurting Google rankings

My question is about specific technicalities of the switch from HTML website to WordPress. I looked through similar questions but my question still remains.

I think my situation is pretty standard.

I’m about to switch my current HTML website to WordPress. My website has been up since 2006.

Main details of the transition:

-My current site is in the /public folder

-Most pages have .php extension

-The WordPress folder is /clickandbuilds/mywebsite (WordPress.org, hosted by 1&1)

-I’ll also need to do 301 redirects for all .php pages to the WP pages

I guess my main question is the following:

Is it safe to just switch my domain from the /public folder to the WordPress folder once everything is ready? I assume it’s a standard procedure – but still wanted to get a second opinion.

Thanks, Leo