You need to change a WordPress settings — you need to enable permalinks. Your WordPress blog URLs look like: example.com/index.php/roman-reigns/ and we need to have them look like example.com/romain-reigns/. This is required to have BuddyPress work.
If we’re lucky, you can go into wp-admin and Settings > Permalinks, then pick anything other than “Default”. Then save, and check if your blog post links have changed, and if they still work.
If they DON’T work, you need to fix that first. There is lots of information on the web about enabling WordPress permalinks, and if you have a good web host, oftentimes they will know how to enable them if they are disabled by default for some reason.