Installing WordPress to root directory with existing static site. Concerns?

When you install WP in the root of an existing site, WP will ‘take over’, and your existing content will be less accessible (if viewable at all).

Since your WP site is developmental (not ready for prime time), your best bet is to install WP in a subfolder, then develop/tweak the site until it is ready to go live.

When ready to go live, you would need to change the htaccess in the root folder to redirect everything to the subfolder. If you are on a hosting plan, you could also redirect the domain via the domain mapping functions in cPanel.

Having the WP site in a subfolder will allow the current site to be visitable until you are ready to redirect visitors to the WP site.