How do I change /blog/ in my blog post addresses to a word like /journal/?

Change the Blog prefix on the Permalink page.

1. Go to Settings → SEO Settings → Permalink.
2. In the Blog field, replace blog with journal.
3. Click Save next to that field.
4. A box shows how many blog posts and menu links will change. Click Approve & apply (or Reject to cancel).

Wcart updates canonical links, the sitemap and links in your menu and content. Old addresses stop working, so add a redirect in Settings → SEO Settings → Redirects for any post links you've shared. The All Blogs, Blog Category and Blog Tag fields change the other blog addresses.