After setting up CF on a WP site with the CF plugin for WP, only the front page and the admin area loaded. Everything else responded with 404. The solution was found in this article:
We were able to resolve the 404 errors be simply saving the permalinks. Go to Settings>Permalinks and click Save Changes (even though you did not make any changes.) That did the trick.
I’ve seen many closed topics but this solution solved it.