“Realname” module is not creating “pretty URLs” for new users?
congratulations on inheriting someone else's work, it was really well documented, right? ;-)

All joking aside, the realname module is used to display alternate names instead of the username.

To get the /user/firstname-lastname urls you would use the pathauto module and configure the "pattern" accordingly. Instead of "user/..." you might want to use the "member/..." to keep things a bit separated. I bet pathauto is already used on your site.

Just change the pattern, delete all user paths and re-create them in a batch.

I also suggest you check all the additionally installed modules and read up on what they are supposed to do. No worries, you'll learn quickly, just use this site a lot. And try to improve your "accept rate" a bit to get more answers ;-)