website has “www” – WP drops “www” – confuse search engines?

My website is https://www.managementhelp.org
My blogs are managementhelp.org/blogs
(I’m told that WP drops the “www” when it installs blogs.)

I’m told that Google might see them as two different domains, and also see part of the content of one site (the “www.managementhelp.org/blogs” part) as being identical in content to the other site (the managementhelp.org site).

I’ve heard that when Google see the same content on two different websites, it thinks that the owner is trying to increase search engine rankings by doing lots of copies of the same content.

SO Google might decrease the rankings of both of my sites.

(I hope I wrote this so it makes sense.)

Is it much of a hassle to get WP to put the “www” back on?

Thanks!