"Discourage search engines from indexing this site" question

Hello,

I want to have a WP installation of my public site on https://www.mydomain.com/wp/ and a WP installation for testing on https://www.mydomain.com/wp_test/

Is it enough if I check the “Discourage search engines from indexing this site” option on my test installation? I don’t want to get a duplicate content penalty or something similar.

After checking the source code of my test site, I saw this was added:
<meta name=’robots’ content=’noindex,follow’ />

Should I change the “follow” to no follow in header.php?

Thanks!